Given the increasingly notable segmentation of underground space by existing subway tunnels, it is dif- ficult to effectively and adequately develop and utilize underground space in busy parts of a city. This study pr...Given the increasingly notable segmentation of underground space by existing subway tunnels, it is dif- ficult to effectively and adequately develop and utilize underground space in busy parts of a city. This study presents a combined construction technology that has been developed for use in underground spaces; it includes a deformation buffer layer, a special grouting technique, jump excavation by compart- ment, back-pressure portal frame technology, a reinforcement technique, and the technology of a steel portioning drum or plate. These technologies have been successfully used in practical engineering. The combined construction technology presented in this paper provides a new method of solving key techni- cal problems in underground spaces in effectively used cross-subway tunnels. As this technology has achieved significant economic and social benefits, it has valuable future applications.展开更多
Carpal tunnel syndrome (CTS) is the most common of all focal neuropathies. Electrodiagnostic (EXD) of CTS has advanced to include Combined Sensory Indexes (CSI) improving the specificity and sensitivity of EXD by empl...Carpal tunnel syndrome (CTS) is the most common of all focal neuropathies. Electrodiagnostic (EXD) of CTS has advanced to include Combined Sensory Indexes (CSI) improving the specificity and sensitivity of EXD by employing intra-hand comparative data. Ultrasound (US) is a popular tool for the assessment of CTS. Cross Sectional Area (CSA) is the most consistent US parameter, but as a single test, it has a similar false negative profile to EXD. This study describes a dual method of CTS interrogation by EXD and US with the results applied to a single numerical score;the Combined Median Score (CMS). This is the product of CSA of median nerve at Carpal Tunnel inlet and CSI. In a series of 100 suspected cases, standard EDX identified 89 positive cases, CSI identified 92 positives, CMS identified 95 positives. This new method further reduced the false negative rate in CTS.展开更多
The lateral response of combined pile-raft foundations(CPRFs)adjacent to tunnel excavation is a challenging problem owing to the complexity of the pile-raft connections.In current engineering practices,the impact of t...The lateral response of combined pile-raft foundations(CPRFs)adjacent to tunnel excavation is a challenging problem owing to the complexity of the pile-raft connections.In current engineering practices,the impact of these connections on the lateral performance of CPRFs is frequently overlooked,despite their importance.To address this issue,this study conducted three-dimensional finite element analyses to evaluate the contribution of pile-raft connections to the tunnelling-induced lateral performance of CPRFs in saturated clay.In the analysis,both passive and active loading at the pile head could be considered by varying the tunnel depth.Several parameter studies,such as relative pile-raft modulus,pile embedded modulus,pile embedded depths,and pile shaft skin friction,were conducted to determine the optimal design parameters for CPRFs.The results indicate that pile-raft connections significantly affect the tunnellinginduced deflections and bending moments of pile groups.Inspired by the results,a simplified design method,the pile-raft connection coefficient Kc was proposed.Additionally,the pile-head restraint percentage was established to make a relationship with the pile-raft connection coefficient in order to assess the pile-raft connection and guide the pile-raft design.In this paper,the recommended range value of Kc is 10–200 and the range value of pile-head restraint percentage is 24%–42%.展开更多
文摘Given the increasingly notable segmentation of underground space by existing subway tunnels, it is dif- ficult to effectively and adequately develop and utilize underground space in busy parts of a city. This study presents a combined construction technology that has been developed for use in underground spaces; it includes a deformation buffer layer, a special grouting technique, jump excavation by compart- ment, back-pressure portal frame technology, a reinforcement technique, and the technology of a steel portioning drum or plate. These technologies have been successfully used in practical engineering. The combined construction technology presented in this paper provides a new method of solving key techni- cal problems in underground spaces in effectively used cross-subway tunnels. As this technology has achieved significant economic and social benefits, it has valuable future applications.
文摘Carpal tunnel syndrome (CTS) is the most common of all focal neuropathies. Electrodiagnostic (EXD) of CTS has advanced to include Combined Sensory Indexes (CSI) improving the specificity and sensitivity of EXD by employing intra-hand comparative data. Ultrasound (US) is a popular tool for the assessment of CTS. Cross Sectional Area (CSA) is the most consistent US parameter, but as a single test, it has a similar false negative profile to EXD. This study describes a dual method of CTS interrogation by EXD and US with the results applied to a single numerical score;the Combined Median Score (CMS). This is the product of CSA of median nerve at Carpal Tunnel inlet and CSI. In a series of 100 suspected cases, standard EDX identified 89 positive cases, CSI identified 92 positives, CMS identified 95 positives. This new method further reduced the false negative rate in CTS.
基金funded by the National Natural Science Foundation of China(Grant No.51878157,52308341)the Natural Science Foundation of Jiangsu Province(Grant No.BK20181282)the China Scholarship Council(CSC202106090083).
文摘The lateral response of combined pile-raft foundations(CPRFs)adjacent to tunnel excavation is a challenging problem owing to the complexity of the pile-raft connections.In current engineering practices,the impact of these connections on the lateral performance of CPRFs is frequently overlooked,despite their importance.To address this issue,this study conducted three-dimensional finite element analyses to evaluate the contribution of pile-raft connections to the tunnelling-induced lateral performance of CPRFs in saturated clay.In the analysis,both passive and active loading at the pile head could be considered by varying the tunnel depth.Several parameter studies,such as relative pile-raft modulus,pile embedded modulus,pile embedded depths,and pile shaft skin friction,were conducted to determine the optimal design parameters for CPRFs.The results indicate that pile-raft connections significantly affect the tunnellinginduced deflections and bending moments of pile groups.Inspired by the results,a simplified design method,the pile-raft connection coefficient Kc was proposed.Additionally,the pile-head restraint percentage was established to make a relationship with the pile-raft connection coefficient in order to assess the pile-raft connection and guide the pile-raft design.In this paper,the recommended range value of Kc is 10–200 and the range value of pile-head restraint percentage is 24%–42%.
