This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages ...This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution. The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow, considering that the maximum value is usually unpredictable. Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage. It was found that the minimum value of deformations （only settlement was considered in this study） due to jetgrouting is no less than 2-3 mm. By contrast, the negative scenario of deformation due to foundation underpinning is clearly demonstrated. Also, this paper provides some general solutions for excavation supporting system as well as for underpinning design.展开更多
This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 ...This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.展开更多
Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just ...Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just like most engineering decisions,there is no unique solution,the research investigated technique of remedying foundation defects and whether there are innovations as regards to the underpinning methods used in Nigeria.To achieve the desired objective structured questionnaire,oral interviews and case study of an ongoing underpinning work were carried out.Result shows that differential settlement with a mean of 2.28 is the most frequent cause of foundation failure.While the continuous strip and reinforced mat with mean of 2.7 and 2.67 respectively,are most frequently used underpinning methods in Nigerian construction industry.Also 81.3%of the respondents agree that underpinning methods adopted are suitable and effective.Professionals in Nigeria have devised unique method of underpinning.It was recommended that proper and adequate site investigation should be carried out.Heavy penalties and sanctions should be meted on those construction firms that employ quack professionals.展开更多
Currently,the pile foundation underpinning technology is widely used when underground transportation infrastructure passes through existing buildings or structures in urban areas.This study aims to investigate stress ...Currently,the pile foundation underpinning technology is widely used when underground transportation infrastructure passes through existing buildings or structures in urban areas.This study aims to investigate stress transfer mechanisms in pile foundations during an underpinning process as well as the influence of shield tunnel construction on pile stability.To this end,the pile foundation underpinning technology used in China’s Shenzhen Metro Line 10 crossing through the bridge pile foundation group of the Guangzhou-Shenzhen highway was analyzed in detailed.The refined numerical simulation of the pile foundation underpinning and shield tunnel construction processes were conducted using the fast Lagrangian analysis of continua in 3 dimensions(FLAC3D)software.The results demonstrate that after the pile foundation underpinned,the previous bridge load system of bridge panel→pile foundation→bearing soil would transform into a bridge panel→existing pile foundation→new underpinning pile→deep bearing soil stratum structure.The overlying load on the underpinned pile could be effectively transferred to a new underpinning pile.In the process of underpinning and tunnel excavation,the settlement and deformation of the foundation can improve the tip resistance and shaft friction of piles,which in turn,can reduce the maximum principal stress in the pile foundation group.The deformation of the bridge pile foundation is mainly caused by ground loss and excavation disturbance generated during shield tunneling as the settlement induced by pile foundation underpinning accounts for approximately 20%-30% of the total settlement.The reduction effects of settlement deformation,lateral displacement,and principal stress are mainly manifested in underpinning piles,while the non-underpinning pile exhibits minimal variation.Meanwhile,the deformation of the segment lining structure of the shield tunnel primarily occurs near the underpinning area of the pile foundation,and it is mainly settlement deformation with a small horizontal displacement.展开更多
Eissa et al.'s review warmly invites readers into the often-overlooked realm of isolated asthenozoospermia(iASZ),a condition marked by reduced sperm motility that affects 16%–24%of male infertility cases.With a n...Eissa et al.'s review warmly invites readers into the often-overlooked realm of isolated asthenozoospermia(iASZ),a condition marked by reduced sperm motility that affects 16%–24%of male infertility cases.With a nod to the authors’dedication,this work masterfully compiles insights into the physiological,genetic,and molecular underpinnings of iASZ,offering a clear guide to its etiology,diagnosis,and management.展开更多
Background Moyamoya disease(MMD)is a rare and complex cerebrovascular disorder characterized by the progressive narrowing of the internal carotid arteries and the formation of compensatory collateral vessels.The etiol...Background Moyamoya disease(MMD)is a rare and complex cerebrovascular disorder characterized by the progressive narrowing of the internal carotid arteries and the formation of compensatory collateral vessels.The etiology of MMD remains enigmatic,making diagnosis and management challenging.The MOYAOMICS project was initiated to investigate the molecular underpinnings of MMD and explore potential diagnostic and therapeutic strategies.Methods The MOYAOMICS project employs a multidisciplinary approach,integrating various omics technologies,including genomics,transcriptomics,proteomics,and metabolomics,to comprehensively examine the molecular signatures associated with MMD pathogenesis.Additionally,we will investigate the potential influence of gut microbiota and brain-gut peptides on MMD development,assessing their suitability as targets for therapeutic strategies and dietary interventions.Radiomics,a specialized field in medical imaging,is utilized to analyze neuroimaging data for early detection and characterization of MMD-related brain changes.Deep learning algorithms are employed to differentiate MMD from other conditions,automating the diagnostic process.We also employ single-cellomics and mass cytometry to precisely study cellular heterogeneity in peripheral blood samples from MMD patients.Conclusions The MOYAOMICS project represents a significant step toward comprehending MMD’s molecular underpinnings.This multidisciplinary approach has the potential to revolutionize early diagnosis,patient stratification,and the development of targeted therapies for MMD.The identification of blood-based biomarkers and the integration of multiple omics data are critical for improving the clinical management of MMD and enhancing patient outcomes for this complex disease.展开更多
文摘This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution. The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow, considering that the maximum value is usually unpredictable. Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage. It was found that the minimum value of deformations （only settlement was considered in this study） due to jetgrouting is no less than 2-3 mm. By contrast, the negative scenario of deformation due to foundation underpinning is clearly demonstrated. Also, this paper provides some general solutions for excavation supporting system as well as for underpinning design.
基金Sponsored by the Research Foundation of State Key Lab of Subtropical Building Science(Grant No.2014KB28)
文摘This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.
文摘Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just like most engineering decisions,there is no unique solution,the research investigated technique of remedying foundation defects and whether there are innovations as regards to the underpinning methods used in Nigeria.To achieve the desired objective structured questionnaire,oral interviews and case study of an ongoing underpinning work were carried out.Result shows that differential settlement with a mean of 2.28 is the most frequent cause of foundation failure.While the continuous strip and reinforced mat with mean of 2.7 and 2.67 respectively,are most frequently used underpinning methods in Nigerian construction industry.Also 81.3%of the respondents agree that underpinning methods adopted are suitable and effective.Professionals in Nigeria have devised unique method of underpinning.It was recommended that proper and adequate site investigation should be carried out.Heavy penalties and sanctions should be meted on those construction firms that employ quack professionals.
基金supported by the Key R&D Program of Sichuan Province,China(No.2019YFG0001).
文摘Currently,the pile foundation underpinning technology is widely used when underground transportation infrastructure passes through existing buildings or structures in urban areas.This study aims to investigate stress transfer mechanisms in pile foundations during an underpinning process as well as the influence of shield tunnel construction on pile stability.To this end,the pile foundation underpinning technology used in China’s Shenzhen Metro Line 10 crossing through the bridge pile foundation group of the Guangzhou-Shenzhen highway was analyzed in detailed.The refined numerical simulation of the pile foundation underpinning and shield tunnel construction processes were conducted using the fast Lagrangian analysis of continua in 3 dimensions(FLAC3D)software.The results demonstrate that after the pile foundation underpinned,the previous bridge load system of bridge panel→pile foundation→bearing soil would transform into a bridge panel→existing pile foundation→new underpinning pile→deep bearing soil stratum structure.The overlying load on the underpinned pile could be effectively transferred to a new underpinning pile.In the process of underpinning and tunnel excavation,the settlement and deformation of the foundation can improve the tip resistance and shaft friction of piles,which in turn,can reduce the maximum principal stress in the pile foundation group.The deformation of the bridge pile foundation is mainly caused by ground loss and excavation disturbance generated during shield tunneling as the settlement induced by pile foundation underpinning accounts for approximately 20%-30% of the total settlement.The reduction effects of settlement deformation,lateral displacement,and principal stress are mainly manifested in underpinning piles,while the non-underpinning pile exhibits minimal variation.Meanwhile,the deformation of the segment lining structure of the shield tunnel primarily occurs near the underpinning area of the pile foundation,and it is mainly settlement deformation with a small horizontal displacement.
文摘Eissa et al.'s review warmly invites readers into the often-overlooked realm of isolated asthenozoospermia(iASZ),a condition marked by reduced sperm motility that affects 16%–24%of male infertility cases.With a nod to the authors’dedication,this work masterfully compiles insights into the physiological,genetic,and molecular underpinnings of iASZ,offering a clear guide to its etiology,diagnosis,and management.
基金supported by the National Natural Science Foundation of China(82301451)the National Key Research and Development Program of China(2021YFC2500502).
文摘Background Moyamoya disease(MMD)is a rare and complex cerebrovascular disorder characterized by the progressive narrowing of the internal carotid arteries and the formation of compensatory collateral vessels.The etiology of MMD remains enigmatic,making diagnosis and management challenging.The MOYAOMICS project was initiated to investigate the molecular underpinnings of MMD and explore potential diagnostic and therapeutic strategies.Methods The MOYAOMICS project employs a multidisciplinary approach,integrating various omics technologies,including genomics,transcriptomics,proteomics,and metabolomics,to comprehensively examine the molecular signatures associated with MMD pathogenesis.Additionally,we will investigate the potential influence of gut microbiota and brain-gut peptides on MMD development,assessing their suitability as targets for therapeutic strategies and dietary interventions.Radiomics,a specialized field in medical imaging,is utilized to analyze neuroimaging data for early detection and characterization of MMD-related brain changes.Deep learning algorithms are employed to differentiate MMD from other conditions,automating the diagnostic process.We also employ single-cellomics and mass cytometry to precisely study cellular heterogeneity in peripheral blood samples from MMD patients.Conclusions The MOYAOMICS project represents a significant step toward comprehending MMD’s molecular underpinnings.This multidisciplinary approach has the potential to revolutionize early diagnosis,patient stratification,and the development of targeted therapies for MMD.The identification of blood-based biomarkers and the integration of multiple omics data are critical for improving the clinical management of MMD and enhancing patient outcomes for this complex disease.
