The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt suppo...The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.展开更多
This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage ...This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.展开更多
The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This pap...The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This paper reports our successful solution of this problem through numerical simulations and a replacement-tunnel scheme in the detailed design stage and close site monitoring in the excavation stage.Particularly,in the detail design stage,mechanical parameters of the shear zone were carefully determined through laboratory experiments and site tests.Then,deformation of the surrounding rocks and the shear zone under high in situ stress conditions was predicted using 3 Dimensional Distinct Element Code(3DEC).Subsequently,a replacement-tunnel scheme was proposed for the treatment on the shear zone to prevent severe unloading relaxation of surrounding rocks.In the construction period,excavation responses were closely monitored on deformations of surrounding rocks and the shear zone.The effect of local cracking in the replacement tunnels on sidewall stability was evaluated using the strength reduction method.These monitoring results were compared with the predicted numerical simulation in the detailed design stage.It is found that the shear zone greatly modified the deformation mode of the cavern surrounding rocks.Without any treatment,rock mass deformation on the downstream sidewall was larger than 125mm and the shearing deformation of the shear zone was 60–70 mm.These preset replacement tunnels can reduce not only the unloading and relaxation of rock masses but also the maximum shearing deformation of the shear zone by 10–20 mm.The predictions by numerical simulation were in good agreement with the monitoring results.The proposed tunnel-replacement scheme can not only restrain the shear zone deformation but also enhance the safety of surrounding rocks and concrete tunnels.This design procedure offers a good reference for interaction between a big underground cavern and a weak layer zone in the future.展开更多
The steel tube arch rib in a large-span concrete-filled steel tube arch bridge has a large span and diameter,which also leads to a larger weld seam scale.Large-scale welding seams will inevitably cause more obvious we...The steel tube arch rib in a large-span concrete-filled steel tube arch bridge has a large span and diameter,which also leads to a larger weld seam scale.Large-scale welding seams will inevitably cause more obvious welding residual stress(WRS).For the purpose of studying the influence of WRS from large-scale welding seam on the mechanical properties of steel tube arch rib during arch rib splicing,test research and numerical simulation analysis on the WRS in arch rib splicing based on the Guangxi Pingnan Third Bridge,which is the world’s largest span concrete-filled steel tube arch bridge,were conducted in this paper,and the distribution pattern of WRS at the arch rib splicing joint was obtained.Subsequently,the WRS was introduced into the mechanical performance analysis of joints and structures to analyze its effects.The findings reveal that the distribution of WRS in the arch rib is greatly influenced by the rib plate,and the axial WRS in the heat-affected zone are primarily tensile,while the circumferential WRS are distributed in an alternating pattern of tensile and compressive stresses along the circumferential direction of the main tube.Under the influence of WRS,the ultimate bearing capacity of the joint is reduced by 29.4%,the initial axial stiffness is reduced by 4.32%,and the vertical deformation of the arch rib structure is increased by 4.7%.展开更多
The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has ...The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has emerged as a critical issue that restricts their development.While scholars have focused on the safety of LRC under multiphysics field coupling,few have noticed the inevitable damage sustained by the primary load-bearing components—the surrounding rock and concrete lining—under high internal pressure,compromising their strength and permeation resistance.This study investigates the impact of damage to the surrounding rock and lining concrete on the stability and airtightness of the CAES cavern.First,a damagepermeability evolution model was established by analyzing cyclic loading and unloading test data on concrete samples.Then,a thermo-hydro-mechanical damage(THM-D)coupling model for the CAES cavern was developed and validated against operational data from the Huntorf plant.The coupling responses of both the surrounding rock and lining were compared and analyzed under three different schemes of the first charging and discharging operation.The results revealed the correlation between the air temperature in the cavern and the injection rate and the uneven damage evolution of the surrounding rock and lining caused by the geostress distribution coupled with the heat transfer process.Through the analysis,a higher air injection rate causes more lining damage and air leakage,posing greater risks to engineering safety and airtightness.However,the reduction of inflation time will weaken this effect to some extent.These findings offer valuable insights into the design,construction,and safe operation of LRC compressed air energy storage systems.展开更多
A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study ...A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study aims to explore the feasibility of an integrated compressed-air energy storage(CAES)coupled with insoluble sediment as the thermal storage media for salt caverns.In order to fulfill this objective,this study presents two steps to analyze the insoluble sediment's thermo-mechanical behavior under ordinary CAES conditions and coupled thermal energy storage(TES)conditions separately.A multiphysics-coupled numerical model was developed to investigate the thermal behavior of insoluble sediments at different heights.Then,a dual-cavity model with a sediment-filled channel was constructed to study the heat storage process in long-and short-term modes.Results demonstrated that sediment effectively protected cavern walls from thermal shocks caused by compressed air,maintaining temperature differentials within 1 K.Dual-cavity simulations revealed the sediment's capability to mitigate the temperature fluctuation of compressed air in caverns,achieving a 66% temperature reduction in the outflow interface during operation.The findings confirmed the feasibility of utilizing insoluble sediments for long-term thermal storage applications involving thermal cycles with ΔT=150 K,attaining a heat storage density of 50 kW·h/m^(3).The results show that the heat capacity of the sediment contributes to the cavern wall's stability and provide references for developing integrated CAES-TES systems in sediment-filled salt caverns.展开更多
Salt cavern hydrogen storage(SCHS)is an important component of large-scale underground hydrogen storage,with advantages such as large hydrogen storage capacity and economic feasibility.However,the uniqueness of the sa...Salt cavern hydrogen storage(SCHS)is an important component of large-scale underground hydrogen storage,with advantages such as large hydrogen storage capacity and economic feasibility.However,the uniqueness of the salt cavern structure and the inherent high risk of hydrogen storage pose a potential leakage risk.This study aims to assess the leakage risk of salt cavern hydrogen storage through a comprehensive assessment.First,the three major influencing factors of leakage risk are summarized,taking into account the unique engineering,geological conditions,and operating conditions of salt cavern storage.Subsequently,the salt cavern hydrogen storage leakage risk evaluation index system was established,and the weights of the evaluation indexes were assigned using the combination assignment method.On the basis of the two-dimensional cloud model,a new leakage risk assessment method was proposed.In addition,the risk level assessment of the salt cavern hydrogen storage facility proposed to be constructed in Pingdingshan City,Henan Province,was carried out.Finally,corresponding risk control and preventive measures are proposed.The results of the study are useful and instructive for the safe construction of deep salt cavern hydrogen storage.展开更多
Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide.Radical prostatectomy(RP)is the standard treatment for localized prostate cancer,but the proced...Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide.Radical prostatectomy(RP)is the standard treatment for localized prostate cancer,but the procedure often results in postoperative erectile dysfunction(ED).The poor efficacy of phosphodiesterase 5 inhibitors after surgery highlights the need to develop new therapies to enhance cavernous nerve regeneration and improve the erectile function of these patients.In the present study,we aimed to examine the potential of heparin-binding epidermal growth factor-like growth factor(HB-EGF)in preserving erectile function in cavernous nerve injury(CNI)mice.We found that HB-EGF expression was reduced significantly on the 1st day after CNI in penile tissue.Ex vivo and in vitro studies showed that HB-EGF promotes major pelvic ganglion neurite sprouting and neuro-2a(N2a)cell migration.In vivo studies showed that exogenous HB-EGF treatment significantly restored the erectile function of CNI mice to 86.9%of sham levels.Immunofluorescence staining showed that mural and neuronal cells were preserved by inducing cell proliferation and reducing apoptosis and reactive oxygen species production.Western blot analysis showed that HB-EGF upregulated protein kinase B and extracellular signal-regulated kinase activation and neurotrophic factor expression.Overall,HB-EGF is a major promising therapeutic agent for treating ED in postoperative RP.展开更多
BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs interve...BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.展开更多
Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical c...Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells(HUC-MSCs)on ED.We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED.Sprague–Dawley rats(total=175)were randomly allocated into five groups.A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs(1×106 cells,5×106 cells,and 1×107 cells in 0.1 ml,respectively).Penile tissues were harvested for histological analysis on 1 day,3 days,7 days,14 days,28 days,60 days,and 90 days postsurgery.It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED.Moreover,there was no significant disparity in the effectiveness of various dosages of HUC-MSCs.However,the expression of endothelial markers(rat endothelial cell antigen-1[RECA-1]and endothelial nitric oxide synthase[eNOS]),smooth muscle markers(alpha smooth muscle actin[α-SMA]and desmin),and neural markers(neurofilament[RECA-1]and neurogenic nitric oxide synthase[nNOS])increased significantly with prolonged treatment time.Masson’s staining demonstrated an increased in the smooth muscle cell(SMC)/collagen ratio.Significant changes were detected in the microstructures of various types of cells.In vivo imaging system(IVIS)analysis showed that at the 1st day,the HUC-MSCs implanted moved to the site of damage.Additionally,the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.展开更多
A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests...A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests were conducted on key sections of steel-concrete composite cable-stayed bridges to analyze the stress-strain evolution of wet joints under environmental factors,constraints,and complex construction processes.The coordinated working performance of the bridge decks was also analyzed.The results indicate that temperature is the key factor affecting the stresses and strains in wet joint concrete.Approximately 7 days after casting the wet joint concrete,the strains at each measurement point of the wet joint are approximately negatively correlated with the temperature change at the measurement point.Different locations within the wet joints have respective impacts,presenting potential weak points.Construction conditions have a certain impact on the stress and strain of the wet joint.The top deck of the steel box girder is not fully bonded to the bottom surface of the wet joints,resulting in a certain strain difference after loading.To further analyze the cooperative working performance of steel box girders and concrete wet joint bridge deck systems,finite element analysis was conducted on composite girder structures.A stiffness calculation method for shear connectors based on numerical simulation was proposed.The results indicate that strain differences can cause interface slip in composite girders.This slip leads to increased deflection of the composite girders and increased tensile stress in the bottom plate of the steel box girders.This study clarifies the stress conditions and factors affecting wet joints during construction,preventing early cracking,and offers precise data for a full bridge finite element model.展开更多
The challenge of wide brine source and its additional problems come from the economy(energy consumption and other costs),security(re-dissolution of surrounding salt rocks),and environment(groundwater pollution by brin...The challenge of wide brine source and its additional problems come from the economy(energy consumption and other costs),security(re-dissolution of surrounding salt rocks),and environment(groundwater pollution by brine)of salt cavern oil storage are worth examining to improve the efficiency of oil storage.Against this background,this work presented an operating mode of salt cavern oil and gas co-storage and using natural gas displacement for petroleum recovery.A gas-oil two-phase flow model with gas dissolution and exsolution was proposed to evaluate the application prospects of the new method precisely.Numerical studies indicated that the gas void fraction at the wellhead under quasi-steady state conditions is approximately 0.153,which belongs to bubbly flow,and the pressure at the wellhead of the central tube increased from 5.54 to 6.12 MPa during the entire transient flow stage,with an increase of 10.47%.Compared to the traditional method of using brine as the working fluid,the pump pressure rises from 2.92 to 14.01 MPa.However,if the new mode can be linked with the salt cavern gas storage and when the initial wellhead gas pressure exceeds 13 MPa,the energy consumption of the new method will be lower than that of the traditional brine-based operational mode.A new empirical formula is proposed to determine the two-phase flow pattern under different operating parameters.A special focus was given to energy consumption for oil recovery,which grows roughly in accordance with the operating pressure and oil recovery rate.However,the energy cost per volume of crude oil remains almost unchanged.This work provided a new solution for the serious brine problem and is expected to achieve petroleum recovery through natural gas displacement.展开更多
Developmental venous anomalies(DVAs)are benign congenital veins that collect normal brain drainage into a single outlet.Cerebral cavernous malformations(CMs)are clusters of thin-walled capillary cavities prone to blee...Developmental venous anomalies(DVAs)are benign congenital veins that collect normal brain drainage into a single outlet.Cerebral cavernous malformations(CMs)are clusters of thin-walled capillary cavities prone to bleeding.When both lesions coexist,the DVA’s altered venous pressure and flow can promote CM formation or rupture.Detecting a DVA abutting an otherwise unexplained intracerebral hemorrhage can therefore raise suspicion of an occult CM as a likely cause,a clue which may be invaluable for daily clinical practice.The main focus of this review is to acknowledge the hallmark imaging appearances of DVAs and CMs,as well as their coexistence,explore the clinical consequences of mixed lesions,and emphasize that recognizing their partnership is vital for an accurate,timely diagnosis and appropriately targeted management.展开更多
Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surroun...Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surrounding rock.The shape and size of the initial damage area as well as their effect on cavern stability remain unclear.Due to the complex geometry and multiphysical couplings,traditional numerical algorithms encounter problems of nonconvergence and low accuracy.These challenges can be addressed through numerical simulations with robust convergence and high accuracy.In this study,the damage area shapes of a CAES cavern are first computed using the concept of damage levels.Then,an iteration algorithm is improved using the generalization a method through the error control and one-way coupling loop for fully coupling equations.Finally,the stability of the CAES cavern with different damage zone shapes is numerically simulated in the thermodynamic process.It is found that this improved algorithm can greatly enhance numerical convergence and accuracy.The nonuniformity of the elastic modulus has a significant impact on the mechanical responses of the CAES cavern.The cavern shape with different damage zones has significant impacts on cavern stability.The initial damage area can delay the responses of temperature and stress.It induces variations of temperature in the range of approximately 1.2 m and variations of stress in the range of 1.5 m from the damage area.展开更多
Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessm...Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessment of the operational safety of such caverns requires an in-depth understanding of the response characteristics of the rock mass subjected to dynamic disturbances.To address this issue,we conducted true triaxial modeling tests and dynamic numerical simulations on large underground caverns to investigate the impact of static stress levels,dynamic load parameters,and input directions on the response characteristics of the surrounding rock mass.The findings reveal that:(1)When subjected to identical incident stress waves and static loads,the surrounding rock mass exhibits the greatest stress response during horizontal incidence.When the incident direction is fixed,the mechanical response is more pronounced at the cavern wall parallel to the direction of dynamic loading.(2)A high initial static stress level specifically enhances the impact of dynamic loading.(3)The response of the surrounding rock mass is directly linked to the amplitude of the incident stress wave.High amplitude results in tensile damage in regions experiencing tensile stress concentration under static loading and shear damage in regions experiencing compressive stress concentration.These results have significant implications for the evaluation and prevention of dynamic disasters in the surrounding rock of underground caverns experiencing dynamic disturbances.展开更多
Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar joint...Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar jointed rock masses(CJRMs)and interlayer shear weakness zones(ISWZs)with inferior mechanical properties,significantly undermines the overall structural stability.To tackle the dynamic loading issues in the process of constructing subterranean caverns,a programmable modeling approach was utilized to reconstruct a large-scale underground cavern model incorporating ISWZs and columnar joints(CJs).By conducting dynamic simulations with varying load orientations,the analyses focused on the failure patterns,deformation characteristics,and acoustic emission activity within the caverns.Results revealed that the failure modes of the underground caverns under dynamic loading were predominantly tensile failures.Under X-direction loading,the failed elements were mainly distributed parallel to the CJs,while under Y-direction loading,they were distributed parallel to the transverse weak structural planes.Furthermore,the dynamic stability of the overall structure varied with the number of caverns.The dual-cavern model demonstrated the highest stability under X-direction loading,while the single-cavern model was the least stable.Under Y-direction loading,the cavern stability increased with the number of caverns.Importantly,different weak structures affected the dynamic response of caverns in different ways;the CJRMs were the primary contributors to structural failure,while ISWZs could mitigate the rock mass failure induced by CJs.The findings could offer valuable insights for the dynamic stability analysis of caverns containing CJRMs and ISWZs.展开更多
BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assiste...BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assisted TIPS(SATIPS)can significantly reduce the risk.AIM To evaluate the clinical efficacy of SATIPS,this study was conducted.METHODS One hundred and seven patients with CTPV and esophagogastric variceal bleeding were recruited from January 2023 to December 2024.The patients were recruited from three different hospitals.Overall,54 patients received SATIPS treatment(SATIPS group),while 53 patients did not receive SATIPS and underwent prophylactic endoscopic sclerosing ligation(control group).Subsequently,survival rates,incidence rates of gastrointestinal bleeding,incidence of hepatic encephalopathy rate,and the incidence of liver failure after treatment in both groups at 3 and 6 months were observed.RESULTS The survival rates for the SATIPS and control groups were 94.4%and 92.5%at 3 months(P value=0.72)and 94.4%and 73.6%at 6 months(P value=0.0051)respectively.The incidence of liver failure was 3.7%and 9.4%at 3 months(P value=0.26)and 3.7%and18.9%at 6 months(P value=0.016);the incidence of gastrointestinal bleeding was 5.6%and 37.7%at 3 months(P value<0.001)and 9.3%and 47.2%(P value<0.001)at 6 months;and the incidence of hepatic encephalopathy was 3.7%and 17.0%at 3 months(P value=0.026)and 7.4%and 26.4%at 6 months(P value=0.026)respectively.CONCLUSION For patients with CTPV,there were no optimal treatment.Regarding long-term efficacy,SATIPS can significantly reduce the rate of rebleeding,hepatic encephalopathy and liver failure,and is associated with better survival.展开更多
Fracture and cavern hydrocarbon reservoirs in carbonates are an important pool type worldwide. The karst cavern reservoirs are easiest to identify on seismic reflection data. The prediction, exploration, and developme...Fracture and cavern hydrocarbon reservoirs in carbonates are an important pool type worldwide. The karst cavern reservoirs are easiest to identify on seismic reflection data. The prediction, exploration, and development of this type of reservoir require theoretical research on seismic wave fields reflected from complex inhomogeneous media. We compute synthetic seismic sections for fluidfilled cavern reservoirs of various heights and widths using random media models and inhomogeneous media elastic wave equations. Results indicate that even caverns significantly smaller than 1/ 4 wavelength are detectible on conventional band-width seismic sections as diffractions migrated into bead-type events. Diffraction amplitude is a function of cavern height and width. We introduce a width-amplitude factor which can be used to calculate the diffraction amplitude of a cavern with a limited width from the diffraction amplitude computed for an infinitely wide cavern.展开更多
基金Project(2023YFC3805700) supported by the National Key Research and Development Program of ChinaProjects(42477166,42277174) supported by the National Natural Science Foundation of China+2 种基金Project(2024JCCXSB01) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(KFJJ24-01M) supported by the State Key Laboratory of Explosion Science and Safety Protection,Beijing Institute of Technology,ChinaProject(HLCX-2024-04) supported by the Open Foundation of Collaborative Innovation Center of Green Development and Ecological Restoration of Mineral Resources,China。
文摘The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns.
基金supported by the State Key Laboratory of Disaster Reduction in Civil Engineering(Grant No.SLDRCE23-02)Ningbo PublicWelfare Fund Project(Grant No.2023S100)the National Key Research and Development Program of China(Grant No.2024YFE0105800).
文摘This study investigates the mechanical response of an underground cavern subjected to cyclic high gas pressure,aiming to establish a theoretical foundation for the design of lined rock caverns(LRCs)for energy storage with high internal pressure,e.g.compressed air energy storage(CAES)underground caverns or hydrogen storage caverns.Initially,the stress paths of the surrounding rock during the excavation,pressurization,and depressurization processes are delineated.Analytical expressions for the stress and deformation of the surrounding rock are derived based on the MohreCoulomb criterion.These expressions are then employed to evaluate the displacement of cavern walls under varying qualities of surrounding rock,the contact pressure between the steel lining and the surrounding rock subject to different gas storage pressures,the load-bearing ratio of the surrounding rock,and the impact of lining thickness on the critical gas pressure.Furthermore,the deformation paths of the surrounding rock are evaluated,along with the effects of tunnel depth and diameter on residual deformation of the surrounding rock,and the critical minimum gas pressure at which the surrounding rock and the lining do not detach.The results indicate that residual deformation of the surrounding rock occurs after depressurization under higher internal pressure for higher-quality rock masses,leading to detachment between the surrounding rock and the steel lining.The findings indicate that thicker linings correspond to higher critical minimum gas pressures.However,for lower-quality surrounding rock,thicker linings correspond to lower critical minimum gas pressures.These findings will provide invaluable insights for the design of LRCs for underground energy storage caverns.
基金Program of China Three Gorges Corporation,Grant/Award Number:BHT 0679-1。
文摘The big underground powerhouse cavern of the China Baihetan hydropower plant is 438m long,34m wide,and 88.7m high.It is cut by a weak interlayer shear zone and its high sidewall poses a huge stability problem.This paper reports our successful solution of this problem through numerical simulations and a replacement-tunnel scheme in the detailed design stage and close site monitoring in the excavation stage.Particularly,in the detail design stage,mechanical parameters of the shear zone were carefully determined through laboratory experiments and site tests.Then,deformation of the surrounding rocks and the shear zone under high in situ stress conditions was predicted using 3 Dimensional Distinct Element Code(3DEC).Subsequently,a replacement-tunnel scheme was proposed for the treatment on the shear zone to prevent severe unloading relaxation of surrounding rocks.In the construction period,excavation responses were closely monitored on deformations of surrounding rocks and the shear zone.The effect of local cracking in the replacement tunnels on sidewall stability was evaluated using the strength reduction method.These monitoring results were compared with the predicted numerical simulation in the detailed design stage.It is found that the shear zone greatly modified the deformation mode of the cavern surrounding rocks.Without any treatment,rock mass deformation on the downstream sidewall was larger than 125mm and the shearing deformation of the shear zone was 60–70 mm.These preset replacement tunnels can reduce not only the unloading and relaxation of rock masses but also the maximum shearing deformation of the shear zone by 10–20 mm.The predictions by numerical simulation were in good agreement with the monitoring results.The proposed tunnel-replacement scheme can not only restrain the shear zone deformation but also enhance the safety of surrounding rocks and concrete tunnels.This design procedure offers a good reference for interaction between a big underground cavern and a weak layer zone in the future.
基金funded by the Science and Technology Research Program of the Chongqing Municipal Education Commission(grant number KJQN202403002).
文摘The steel tube arch rib in a large-span concrete-filled steel tube arch bridge has a large span and diameter,which also leads to a larger weld seam scale.Large-scale welding seams will inevitably cause more obvious welding residual stress(WRS).For the purpose of studying the influence of WRS from large-scale welding seam on the mechanical properties of steel tube arch rib during arch rib splicing,test research and numerical simulation analysis on the WRS in arch rib splicing based on the Guangxi Pingnan Third Bridge,which is the world’s largest span concrete-filled steel tube arch bridge,were conducted in this paper,and the distribution pattern of WRS at the arch rib splicing joint was obtained.Subsequently,the WRS was introduced into the mechanical performance analysis of joints and structures to analyze its effects.The findings reveal that the distribution of WRS in the arch rib is greatly influenced by the rib plate,and the axial WRS in the heat-affected zone are primarily tensile,while the circumferential WRS are distributed in an alternating pattern of tensile and compressive stresses along the circumferential direction of the main tube.Under the influence of WRS,the ultimate bearing capacity of the joint is reduced by 29.4%,the initial axial stiffness is reduced by 4.32%,and the vertical deformation of the arch rib structure is increased by 4.7%.
基金National Natural Science Foundation of China,Grant/Award Number:U23B20147Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS),Grant/Award Number:ZDBS-LY-DQC022+1 种基金Hubei Provincial Natural Science Foundation of China,Grant/Award Number:2023AFB346Knowledge Innovation Program of Wuhan-Shuguang Project,Grant/Award Number:2023010201020278。
文摘The lined rock cavern(LRC)compressed air energy storage(CAES)system is currently regarded as one of the most promising methods for large-scale energy storage.However,the safety of LRC under high internal pressure has emerged as a critical issue that restricts their development.While scholars have focused on the safety of LRC under multiphysics field coupling,few have noticed the inevitable damage sustained by the primary load-bearing components—the surrounding rock and concrete lining—under high internal pressure,compromising their strength and permeation resistance.This study investigates the impact of damage to the surrounding rock and lining concrete on the stability and airtightness of the CAES cavern.First,a damagepermeability evolution model was established by analyzing cyclic loading and unloading test data on concrete samples.Then,a thermo-hydro-mechanical damage(THM-D)coupling model for the CAES cavern was developed and validated against operational data from the Huntorf plant.The coupling responses of both the surrounding rock and lining were compared and analyzed under three different schemes of the first charging and discharging operation.The results revealed the correlation between the air temperature in the cavern and the injection rate and the uneven damage evolution of the surrounding rock and lining caused by the geostress distribution coupled with the heat transfer process.Through the analysis,a higher air injection rate causes more lining damage and air leakage,posing greater risks to engineering safety and airtightness.However,the reduction of inflation time will weaken this effect to some extent.These findings offer valuable insights into the design,construction,and safe operation of LRC compressed air energy storage systems.
基金National Natural Science Foundation of China,Grant/Award Number:52090081 and 42477180Beijing Nova Program,Grant/Award Number:20250484906+2 种基金National Science and Technology Major Project of China,Grant/Award Number:2024ZD1003600SINOPEC Science and Technology Department Project,Grant/Award Number:P25006Young Elite Scientist Sponsorship Program by China Association for Science and Technology,Grant/Award Number:YESS20220300。
文摘A significant number of salt caverns have high proportions of insoluble sediments,but the thermal storage utilization potential of insoluble sediments remains understudied within current research.Therefore,this study aims to explore the feasibility of an integrated compressed-air energy storage(CAES)coupled with insoluble sediment as the thermal storage media for salt caverns.In order to fulfill this objective,this study presents two steps to analyze the insoluble sediment's thermo-mechanical behavior under ordinary CAES conditions and coupled thermal energy storage(TES)conditions separately.A multiphysics-coupled numerical model was developed to investigate the thermal behavior of insoluble sediments at different heights.Then,a dual-cavity model with a sediment-filled channel was constructed to study the heat storage process in long-and short-term modes.Results demonstrated that sediment effectively protected cavern walls from thermal shocks caused by compressed air,maintaining temperature differentials within 1 K.Dual-cavity simulations revealed the sediment's capability to mitigate the temperature fluctuation of compressed air in caverns,achieving a 66% temperature reduction in the outflow interface during operation.The findings confirmed the feasibility of utilizing insoluble sediments for long-term thermal storage applications involving thermal cycles with ΔT=150 K,attaining a heat storage density of 50 kW·h/m^(3).The results show that the heat capacity of the sediment contributes to the cavern wall's stability and provide references for developing integrated CAES-TES systems in sediment-filled salt caverns.
基金Youth Innovation Promotion Association of the Chinese Academy of Sciences,Grant/Award Number:No.Y2023089Excellent Young Scientists Fund,Grant/Award Number:No.52122403National Natural Science Foundation of China,Grant/Award Number:No.52374069。
文摘Salt cavern hydrogen storage(SCHS)is an important component of large-scale underground hydrogen storage,with advantages such as large hydrogen storage capacity and economic feasibility.However,the uniqueness of the salt cavern structure and the inherent high risk of hydrogen storage pose a potential leakage risk.This study aims to assess the leakage risk of salt cavern hydrogen storage through a comprehensive assessment.First,the three major influencing factors of leakage risk are summarized,taking into account the unique engineering,geological conditions,and operating conditions of salt cavern storage.Subsequently,the salt cavern hydrogen storage leakage risk evaluation index system was established,and the weights of the evaluation indexes were assigned using the combination assignment method.On the basis of the two-dimensional cloud model,a new leakage risk assessment method was proposed.In addition,the risk level assessment of the salt cavern hydrogen storage facility proposed to be constructed in Pingdingshan City,Henan Province,was carried out.Finally,corresponding risk control and preventive measures are proposed.The results of the study are useful and instructive for the safe construction of deep salt cavern hydrogen storage.
文摘Prostate cancer is the second most common malignancy and the sixth leading cause of cancer-related death in men worldwide.Radical prostatectomy(RP)is the standard treatment for localized prostate cancer,but the procedure often results in postoperative erectile dysfunction(ED).The poor efficacy of phosphodiesterase 5 inhibitors after surgery highlights the need to develop new therapies to enhance cavernous nerve regeneration and improve the erectile function of these patients.In the present study,we aimed to examine the potential of heparin-binding epidermal growth factor-like growth factor(HB-EGF)in preserving erectile function in cavernous nerve injury(CNI)mice.We found that HB-EGF expression was reduced significantly on the 1st day after CNI in penile tissue.Ex vivo and in vitro studies showed that HB-EGF promotes major pelvic ganglion neurite sprouting and neuro-2a(N2a)cell migration.In vivo studies showed that exogenous HB-EGF treatment significantly restored the erectile function of CNI mice to 86.9%of sham levels.Immunofluorescence staining showed that mural and neuronal cells were preserved by inducing cell proliferation and reducing apoptosis and reactive oxygen species production.Western blot analysis showed that HB-EGF upregulated protein kinase B and extracellular signal-regulated kinase activation and neurotrophic factor expression.Overall,HB-EGF is a major promising therapeutic agent for treating ED in postoperative RP.
文摘BACKGROUND Hepatic hemangioma represents the most common benign primary hepatic neo-plasm.Although most such tumors are small and asymptomatic,giant cavernous hemangioma(GCH)is frequently symptomatic,and needs intervention.More-over,diffuse hepatic hemangiomatosis(DHH)is not rare in the liver parenchyma adjacent to a GCH.The management strategy for hepatic hemangiomas can differ depending on the presence of associated hemangiomatosis and the amount and distribution of the residual hepatic parenchyma.CASE SUMMARY Herein,we report two patients with GCH coexistent with DHH successfully treated by laparoscopic microwave ablation.The two GCHs were ablated com-pletely and the ablated zone atrophied obviously in imaging follow-ups after ablation.Surprisingly,there was a trend toward gradual reduction and dimini-shment of DHH.CONCLUSION Thermal ablation treatment might be an effective and less invasive treatment for GCH coexistent with DHH around the hemangioma.
基金supported by the Xuzhou City 2022 Special Program for Promoting Science and Technology Innovation(grant No.KC22096)Shandong Provincial Hospital Research Incubation Fund(No.2022FY063).
文摘Stem cell treatment may enhance erectile dysfunction(ED)in individuals with cavernous nerve injury(CNI).Nevertheless,no investigations have directly ascertained the implications of varying amounts of human umbilical cord-derived mesenchymal stem cells(HUC-MSCs)on ED.We compare the efficacy of three various doses of HUC-MSCs as a therapeutic strategy for ED.Sprague–Dawley rats(total=175)were randomly allocated into five groups.A total of 35 rats underwent sham surgery and 140 rats endured bilateral CNI and were treated with vehicles or doses of HUC-MSCs(1×106 cells,5×106 cells,and 1×107 cells in 0.1 ml,respectively).Penile tissues were harvested for histological analysis on 1 day,3 days,7 days,14 days,28 days,60 days,and 90 days postsurgery.It was found that varying dosages of HUC-MSCs enhanced the erectile function of rats with bilateral CNI and ED.Moreover,there was no significant disparity in the effectiveness of various dosages of HUC-MSCs.However,the expression of endothelial markers(rat endothelial cell antigen-1[RECA-1]and endothelial nitric oxide synthase[eNOS]),smooth muscle markers(alpha smooth muscle actin[α-SMA]and desmin),and neural markers(neurofilament[RECA-1]and neurogenic nitric oxide synthase[nNOS])increased significantly with prolonged treatment time.Masson’s staining demonstrated an increased in the smooth muscle cell(SMC)/collagen ratio.Significant changes were detected in the microstructures of various types of cells.In vivo imaging system(IVIS)analysis showed that at the 1st day,the HUC-MSCs implanted moved to the site of damage.Additionally,the oxidative stress levels were dramatically reduced in the penises of rats administered with HUC-MSCs.
文摘A steel-concrete composite cable-stayed bridge features integrated steel girders and concrete decks linked by shear connectors to support loads,but stress concentration in wet joints can lead to cracking.In-situ tests were conducted on key sections of steel-concrete composite cable-stayed bridges to analyze the stress-strain evolution of wet joints under environmental factors,constraints,and complex construction processes.The coordinated working performance of the bridge decks was also analyzed.The results indicate that temperature is the key factor affecting the stresses and strains in wet joint concrete.Approximately 7 days after casting the wet joint concrete,the strains at each measurement point of the wet joint are approximately negatively correlated with the temperature change at the measurement point.Different locations within the wet joints have respective impacts,presenting potential weak points.Construction conditions have a certain impact on the stress and strain of the wet joint.The top deck of the steel box girder is not fully bonded to the bottom surface of the wet joints,resulting in a certain strain difference after loading.To further analyze the cooperative working performance of steel box girders and concrete wet joint bridge deck systems,finite element analysis was conducted on composite girder structures.A stiffness calculation method for shear connectors based on numerical simulation was proposed.The results indicate that strain differences can cause interface slip in composite girders.This slip leads to increased deflection of the composite girders and increased tensile stress in the bottom plate of the steel box girders.This study clarifies the stress conditions and factors affecting wet joints during construction,preventing early cracking,and offers precise data for a full bridge finite element model.
基金The financial support from the National Science and Technology Major Project,China(No.2024ZD1004107)the Natural Science Foundation of Wuhan(No.2024040701010062)is greatly appreciated。
文摘The challenge of wide brine source and its additional problems come from the economy(energy consumption and other costs),security(re-dissolution of surrounding salt rocks),and environment(groundwater pollution by brine)of salt cavern oil storage are worth examining to improve the efficiency of oil storage.Against this background,this work presented an operating mode of salt cavern oil and gas co-storage and using natural gas displacement for petroleum recovery.A gas-oil two-phase flow model with gas dissolution and exsolution was proposed to evaluate the application prospects of the new method precisely.Numerical studies indicated that the gas void fraction at the wellhead under quasi-steady state conditions is approximately 0.153,which belongs to bubbly flow,and the pressure at the wellhead of the central tube increased from 5.54 to 6.12 MPa during the entire transient flow stage,with an increase of 10.47%.Compared to the traditional method of using brine as the working fluid,the pump pressure rises from 2.92 to 14.01 MPa.However,if the new mode can be linked with the salt cavern gas storage and when the initial wellhead gas pressure exceeds 13 MPa,the energy consumption of the new method will be lower than that of the traditional brine-based operational mode.A new empirical formula is proposed to determine the two-phase flow pattern under different operating parameters.A special focus was given to energy consumption for oil recovery,which grows roughly in accordance with the operating pressure and oil recovery rate.However,the energy cost per volume of crude oil remains almost unchanged.This work provided a new solution for the serious brine problem and is expected to achieve petroleum recovery through natural gas displacement.
文摘Developmental venous anomalies(DVAs)are benign congenital veins that collect normal brain drainage into a single outlet.Cerebral cavernous malformations(CMs)are clusters of thin-walled capillary cavities prone to bleeding.When both lesions coexist,the DVA’s altered venous pressure and flow can promote CM formation or rupture.Detecting a DVA abutting an otherwise unexplained intracerebral hemorrhage can therefore raise suspicion of an occult CM as a likely cause,a clue which may be invaluable for daily clinical practice.The main focus of this review is to acknowledge the hallmark imaging appearances of DVAs and CMs,as well as their coexistence,explore the clinical consequences of mixed lesions,and emphasize that recognizing their partnership is vital for an accurate,timely diagnosis and appropriately targeted management.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFE0129100National Natural Science Foundation of China,Grant/Award Number:51674246+1 种基金Graduate Innovation Program of China University of Mining and Technology,Grant/Award Number:2023WLJCRCZL046Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX23_2660。
文摘Compressed air energy storage(CAES)caverns transformed from horseshoe-shaped roadways in abandoned coal mines still face unclear mechanisms of force transfer,especially in the presence of initial damage in the surrounding rock.The shape and size of the initial damage area as well as their effect on cavern stability remain unclear.Due to the complex geometry and multiphysical couplings,traditional numerical algorithms encounter problems of nonconvergence and low accuracy.These challenges can be addressed through numerical simulations with robust convergence and high accuracy.In this study,the damage area shapes of a CAES cavern are first computed using the concept of damage levels.Then,an iteration algorithm is improved using the generalization a method through the error control and one-way coupling loop for fully coupling equations.Finally,the stability of the CAES cavern with different damage zone shapes is numerically simulated in the thermodynamic process.It is found that this improved algorithm can greatly enhance numerical convergence and accuracy.The nonuniformity of the elastic modulus has a significant impact on the mechanical responses of the CAES cavern.The cavern shape with different damage zones has significant impacts on cavern stability.The initial damage area can delay the responses of temperature and stress.It induces variations of temperature in the range of approximately 1.2 m and variations of stress in the range of 1.5 m from the damage area.
基金supported by the National Natural Science Foundation of China (Grant No.52279116)the Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of China (Grant No.U1865203).
文摘Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessment of the operational safety of such caverns requires an in-depth understanding of the response characteristics of the rock mass subjected to dynamic disturbances.To address this issue,we conducted true triaxial modeling tests and dynamic numerical simulations on large underground caverns to investigate the impact of static stress levels,dynamic load parameters,and input directions on the response characteristics of the surrounding rock mass.The findings reveal that:(1)When subjected to identical incident stress waves and static loads,the surrounding rock mass exhibits the greatest stress response during horizontal incidence.When the incident direction is fixed,the mechanical response is more pronounced at the cavern wall parallel to the direction of dynamic loading.(2)A high initial static stress level specifically enhances the impact of dynamic loading.(3)The response of the surrounding rock mass is directly linked to the amplitude of the incident stress wave.High amplitude results in tensile damage in regions experiencing tensile stress concentration under static loading and shear damage in regions experiencing compressive stress concentration.These results have significant implications for the evaluation and prevention of dynamic disasters in the surrounding rock of underground caverns experiencing dynamic disturbances.
基金funded by the National Natural Science Foundation of China(Grant Nos.42077251,41807269,and U1865203).
文摘Rock masses are often exposed to dynamic loads such as earthquakes and mechanical disturbances in practical engineering scenarios.The existence of underground caverns and weak geological structures like columnar jointed rock masses(CJRMs)and interlayer shear weakness zones(ISWZs)with inferior mechanical properties,significantly undermines the overall structural stability.To tackle the dynamic loading issues in the process of constructing subterranean caverns,a programmable modeling approach was utilized to reconstruct a large-scale underground cavern model incorporating ISWZs and columnar joints(CJs).By conducting dynamic simulations with varying load orientations,the analyses focused on the failure patterns,deformation characteristics,and acoustic emission activity within the caverns.Results revealed that the failure modes of the underground caverns under dynamic loading were predominantly tensile failures.Under X-direction loading,the failed elements were mainly distributed parallel to the CJs,while under Y-direction loading,they were distributed parallel to the transverse weak structural planes.Furthermore,the dynamic stability of the overall structure varied with the number of caverns.The dual-cavern model demonstrated the highest stability under X-direction loading,while the single-cavern model was the least stable.Under Y-direction loading,the cavern stability increased with the number of caverns.Importantly,different weak structures affected the dynamic response of caverns in different ways;the CJRMs were the primary contributors to structural failure,while ISWZs could mitigate the rock mass failure induced by CJs.The findings could offer valuable insights for the dynamic stability analysis of caverns containing CJRMs and ISWZs.
文摘BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is contraindicated for patients with cavernous transformation of the portal vein(CTPV)due to high surgery-related mortality risk.However,surgically assisted TIPS(SATIPS)can significantly reduce the risk.AIM To evaluate the clinical efficacy of SATIPS,this study was conducted.METHODS One hundred and seven patients with CTPV and esophagogastric variceal bleeding were recruited from January 2023 to December 2024.The patients were recruited from three different hospitals.Overall,54 patients received SATIPS treatment(SATIPS group),while 53 patients did not receive SATIPS and underwent prophylactic endoscopic sclerosing ligation(control group).Subsequently,survival rates,incidence rates of gastrointestinal bleeding,incidence of hepatic encephalopathy rate,and the incidence of liver failure after treatment in both groups at 3 and 6 months were observed.RESULTS The survival rates for the SATIPS and control groups were 94.4%and 92.5%at 3 months(P value=0.72)and 94.4%and 73.6%at 6 months(P value=0.0051)respectively.The incidence of liver failure was 3.7%and 9.4%at 3 months(P value=0.26)and 3.7%and18.9%at 6 months(P value=0.016);the incidence of gastrointestinal bleeding was 5.6%and 37.7%at 3 months(P value<0.001)and 9.3%and 47.2%(P value<0.001)at 6 months;and the incidence of hepatic encephalopathy was 3.7%and 17.0%at 3 months(P value=0.026)and 7.4%and 26.4%at 6 months(P value=0.026)respectively.CONCLUSION For patients with CTPV,there were no optimal treatment.Regarding long-term efficacy,SATIPS can significantly reduce the rate of rebleeding,hepatic encephalopathy and liver failure,and is associated with better survival.
基金This research project is sponsored by Nation’s Natural Science Found of China (No. 40174034 and 40274038) as well as theOpening Found Projects of the CNPC geophysical exploration key laboratory (No. GPKL0207).
文摘Fracture and cavern hydrocarbon reservoirs in carbonates are an important pool type worldwide. The karst cavern reservoirs are easiest to identify on seismic reflection data. The prediction, exploration, and development of this type of reservoir require theoretical research on seismic wave fields reflected from complex inhomogeneous media. We compute synthetic seismic sections for fluidfilled cavern reservoirs of various heights and widths using random media models and inhomogeneous media elastic wave equations. Results indicate that even caverns significantly smaller than 1/ 4 wavelength are detectible on conventional band-width seismic sections as diffractions migrated into bead-type events. Diffraction amplitude is a function of cavern height and width. We introduce a width-amplitude factor which can be used to calculate the diffraction amplitude of a cavern with a limited width from the diffraction amplitude computed for an infinitely wide cavern.
