The objective of this study is to investigate critical velocity and smoke maximum temperature beneath the ceiling in the connected area of branch tunnel with varying fire locations.The fire sources were located in the...The objective of this study is to investigate critical velocity and smoke maximum temperature beneath the ceiling in the connected area of branch tunnel with varying fire locations.The fire sources were located in the divergent connected area of the branch tunnel,to imitate traffic accidents near the branch point.A 1/20 scale model branch tunnel was built including main line before branch,main line after branch,and ramp.Experimental tests and numerical simulations were performed to explore smoke movement characteristics with longitudinal ventilation.The results showed that the enlarged cross-sectional area in branch tunnel caused the shortening of the back-layering length,and a modified model of back-layering length was proposed.The higher tunnel height in this work affected the critical condition of large fire;it caused a larger transition point of dimensionless critical velocity.A revised model was proposed for the maximum temperature rise of tunnel fires in the connected area of branch tunnel.The critical velocity kept unchanged when the branch angle increased from 0°to 20°because there is little change in the longitudinal smoke temperature.As the local tunnel width of fire source was increased,the required critical velocity was increased while the local effective velocity kept nearly the same.展开更多
冬奥会山区综合管廊1^(#)支洞区域地质背景复杂,为了科学地指导1^(#)支洞路由选址工作,通过地质测绘、钻探、工程物探、原位测试、水文试验、室内试验的综合勘察技术方法对综合管廊1^(#)支洞的主要工程地质问题进行了深入研究与分析。...冬奥会山区综合管廊1^(#)支洞区域地质背景复杂,为了科学地指导1^(#)支洞路由选址工作,通过地质测绘、钻探、工程物探、原位测试、水文试验、室内试验的综合勘察技术方法对综合管廊1^(#)支洞的主要工程地质问题进行了深入研究与分析。结果研究表明,断层带破碎、突水涌水、围岩稳定为1^(#)支洞突出的工程地质问题。在此基础上,确定了综合管廊1^(#)支洞地质选线原则,并结合建筑信息模型(building information modeling,BIM)三维模型,对北线、南线方案进行了比选,确定了地质条件相对较优的南线方案。研究方法可为存在类似工程地质条件或工程地质问题的山区地下工程的地质选线提供一定的参考与借鉴。展开更多
基金This research was supported by the National Nature Science Foundation of China(No.52076066)Key Research and Development Project of Zhejiang Province(No.2018C03029)+1 种基金Zhejiang Provincial Natural Science Foundation of China(No.LQ19E040005)Fellowship of China Postdoctoral Science Foundation(No.2021M693042).
文摘The objective of this study is to investigate critical velocity and smoke maximum temperature beneath the ceiling in the connected area of branch tunnel with varying fire locations.The fire sources were located in the divergent connected area of the branch tunnel,to imitate traffic accidents near the branch point.A 1/20 scale model branch tunnel was built including main line before branch,main line after branch,and ramp.Experimental tests and numerical simulations were performed to explore smoke movement characteristics with longitudinal ventilation.The results showed that the enlarged cross-sectional area in branch tunnel caused the shortening of the back-layering length,and a modified model of back-layering length was proposed.The higher tunnel height in this work affected the critical condition of large fire;it caused a larger transition point of dimensionless critical velocity.A revised model was proposed for the maximum temperature rise of tunnel fires in the connected area of branch tunnel.The critical velocity kept unchanged when the branch angle increased from 0°to 20°because there is little change in the longitudinal smoke temperature.As the local tunnel width of fire source was increased,the required critical velocity was increased while the local effective velocity kept nearly the same.
文摘冬奥会山区综合管廊1^(#)支洞区域地质背景复杂,为了科学地指导1^(#)支洞路由选址工作,通过地质测绘、钻探、工程物探、原位测试、水文试验、室内试验的综合勘察技术方法对综合管廊1^(#)支洞的主要工程地质问题进行了深入研究与分析。结果研究表明,断层带破碎、突水涌水、围岩稳定为1^(#)支洞突出的工程地质问题。在此基础上,确定了综合管廊1^(#)支洞地质选线原则,并结合建筑信息模型(building information modeling,BIM)三维模型,对北线、南线方案进行了比选,确定了地质条件相对较优的南线方案。研究方法可为存在类似工程地质条件或工程地质问题的山区地下工程的地质选线提供一定的参考与借鉴。
