The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex whic...The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex which was located in Shanghai. The effects on water pressure and building settlements were analyzed as well. The numerical analyses by finite element method (FEM) were conducted. It showed that the soil under the excavation base continued to heave during the following certain construction stage. It also found that the bearing capacity of uplift piles which supported the buildings affected the structure quality significantly. The conclusions can be applied in future projects.展开更多
Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space ar...Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space areas and densely populated.Once a fire occurs in the complex underground space,it will cause huge property losses and casualties.In order to reduce the risk of fire,it is necessary to deeply understand the development rules and characteristics of fire in the complex underground space of the city.This article has mainly carried on the following work:(I)A particularly complex model of the multi‐storey subway station was built.On this basis,three groups of comparative experiments were conducted to study the effects of fire power,fire location and smoke control system on fire development,and the conclusion that fire location is the most important factor for fire development was obtained;(II)In order to explore the entire space fire and the local space fire,CFD(Computational Fluid Dynamics)is used to build a large‐size fire model and a small‐size fire model respectively;(III)Multiple detector data as temperature slices were built,and it is expected to make full use of the simulation data to deduce the important index of fire location in the early stage of fire.All of the works in this paper will provide reference experimental data for the prevention and firefighting of a sudden fire in the complex underground space.展开更多
The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismi...The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismic data,resulting in difficulties in clarifying relevant structures.The key target formation,the Mid-Permian Qixia Fm,is deeply buried with thin reservoirs and high heterogeneity,which brings great challenges to seismic prediction.Under such circumstances,researches have been conducted jointly in terms of seismic data acquisition,processing and interpretation,and finally some relevant seismic survey technologies were developed suitable for surface/underground complex structures.Through surface structural surveys,dynamic deep-well lithologic identification,single-point detector deployment and process optimization,acquisition parameters can be excited.In addition,by using an observation systemwith high-coverage,wide-azimuth and huge-displacement,quality of acquired seismic data can be enhanced dramatically.Seismic imaging technologies for complex structures have been developed to enhance the quality of images for deep formations.These technologies are dominated by microscopic logging-constrained tomography static correction,high-resolution processing with fidelity and amplitude preservation and all-around PSDM in an angular domain.By using high-resolution gravity,magnetic and electric data,details related to geological structures and faults can be identified.In combination with fine seismic data interpretation,structural details and fault features can be verified effectively.Based on forwardmodeling and fine seismic calibration of reservoirs in individualwells,suitable attributes can be identified for predictions related to the distribution of reservoirs.By using all these auxiliary technologies,a large-scale structuralelithologic composite trap with a total area of 1223 km^(2) has been discovered in the NW Sichuan Basin.The Shuangyushi-Jiangyou area as a whole distributes on structural highs.In the areas to the south of Shuangyushi,the Qixia Fm dolomite reservoirs of platform margins are continuously developed.In conclusion,these auxiliary technologies can effectively allow trap identification and thin reservoir prediction in complex structures in the study area.In addition to clarifying the exploration orientation and providing a necessarily technical supports forwell development,these technologies help to accelerate the construction of demonstration projects for the exploration and development of deep marine carbonate formations.展开更多
Taking vertical shaft construction of cutter transformation of the Beijing underground diameter shield for example,the design and construction of cutter structure transformation under complex boundary conditions for l...Taking vertical shaft construction of cutter transformation of the Beijing underground diameter shield for example,the design and construction of cutter structure transformation under complex boundary conditions for large diameter shield were discussed.Practice about how to ensure the structure safety of the shaft as well as well-coordinated shield construction was explored,and reliable solutions were provided successfully,which can provide reference for similar projects.展开更多
基金the National Natural Science Foundation of China (No. 50679041)
文摘The effects of excavation unloading, construction reloading and underground water on basal heave of excavation projects were presented and analyzed based on the measurement results of an underground urban complex which was located in Shanghai. The effects on water pressure and building settlements were analyzed as well. The numerical analyses by finite element method (FEM) were conducted. It showed that the soil under the excavation base continued to heave during the following certain construction stage. It also found that the bearing capacity of uplift piles which supported the buildings affected the structure quality significantly. The conclusions can be applied in future projects.
基金supported by Shenzhen Science and Technology Innovation Commission(NO.KCXFZ20211020163402004).
文摘Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space areas and densely populated.Once a fire occurs in the complex underground space,it will cause huge property losses and casualties.In order to reduce the risk of fire,it is necessary to deeply understand the development rules and characteristics of fire in the complex underground space of the city.This article has mainly carried on the following work:(I)A particularly complex model of the multi‐storey subway station was built.On this basis,three groups of comparative experiments were conducted to study the effects of fire power,fire location and smoke control system on fire development,and the conclusion that fire location is the most important factor for fire development was obtained;(II)In order to explore the entire space fire and the local space fire,CFD(Computational Fluid Dynamics)is used to build a large‐size fire model and a small‐size fire model respectively;(III)Multiple detector data as temperature slices were built,and it is expected to make full use of the simulation data to deduce the important index of fire location in the early stage of fire.All of the works in this paper will provide reference experimental data for the prevention and firefighting of a sudden fire in the complex underground space.
基金Project supported by the National Major Science and Technology Project“Development of Large Oil/Gas Fields and Coalbed Methane”(No.2016ZX05004-005&2016ZX05007-004)the CNPC Major Science and Technology Project“Research and application of key technologies for maintaining gas productivity of 30 billion cubic meters in Southwest Oil and Gas Fields”(No.2016E-06,2016E-0602,2016E-0603&2016E-0604).
文摘The northern Sichuan Basin,spreading in the northern section of the Longmenshan Fault Fold Belt,is characterized by dramatic fluctuations in the surface landforms,development of abdominal faults,and low-quality seismic data,resulting in difficulties in clarifying relevant structures.The key target formation,the Mid-Permian Qixia Fm,is deeply buried with thin reservoirs and high heterogeneity,which brings great challenges to seismic prediction.Under such circumstances,researches have been conducted jointly in terms of seismic data acquisition,processing and interpretation,and finally some relevant seismic survey technologies were developed suitable for surface/underground complex structures.Through surface structural surveys,dynamic deep-well lithologic identification,single-point detector deployment and process optimization,acquisition parameters can be excited.In addition,by using an observation systemwith high-coverage,wide-azimuth and huge-displacement,quality of acquired seismic data can be enhanced dramatically.Seismic imaging technologies for complex structures have been developed to enhance the quality of images for deep formations.These technologies are dominated by microscopic logging-constrained tomography static correction,high-resolution processing with fidelity and amplitude preservation and all-around PSDM in an angular domain.By using high-resolution gravity,magnetic and electric data,details related to geological structures and faults can be identified.In combination with fine seismic data interpretation,structural details and fault features can be verified effectively.Based on forwardmodeling and fine seismic calibration of reservoirs in individualwells,suitable attributes can be identified for predictions related to the distribution of reservoirs.By using all these auxiliary technologies,a large-scale structuralelithologic composite trap with a total area of 1223 km^(2) has been discovered in the NW Sichuan Basin.The Shuangyushi-Jiangyou area as a whole distributes on structural highs.In the areas to the south of Shuangyushi,the Qixia Fm dolomite reservoirs of platform margins are continuously developed.In conclusion,these auxiliary technologies can effectively allow trap identification and thin reservoir prediction in complex structures in the study area.In addition to clarifying the exploration orientation and providing a necessarily technical supports forwell development,these technologies help to accelerate the construction of demonstration projects for the exploration and development of deep marine carbonate formations.
文摘Taking vertical shaft construction of cutter transformation of the Beijing underground diameter shield for example,the design and construction of cutter structure transformation under complex boundary conditions for large diameter shield were discussed.Practice about how to ensure the structure safety of the shaft as well as well-coordinated shield construction was explored,and reliable solutions were provided successfully,which can provide reference for similar projects.
