日喀则—吉隆铁路活动断裂特征及其工程影响分析

日喀则至吉隆铁路位于藏南地区板块碰撞的构造边界带上,跨越定结、岗嘎和佩枯错三条大的第四纪活动裂谷,各裂谷内分布的活动断层对铁路的选线及工程设计具有重要影响。通过对日吉铁路沿线各裂谷内共25条断裂的现场调查测试,查明工程共穿越晚更新世活动断裂10条,其中有全新世活动断裂4条,分别为定结裂谷中的定结、郭家、登么错断裂和佩枯错裂谷中的岗彭庆断裂。对于定结、郭家断裂,可选择其活动性相对较弱的南段以简易工程通过,而对全线全新世活动性最强的登么错断裂,建议以路基形式通过。岗彭庆断裂带因未来地震危险性高,应避免以隧道工程通过。

Characteristics of active faults and their engineering influence analysis in domestic section of Shigatse - Jilong Railway

Shigatse-Jilong Railway is located on the tectonic boundary zone of plate collision in southern Tibet, Across the three major Quaternary active rifts of Dingjie, Gangga and Peikucuo. The active faults distributed in each rift valley have an important influence on railway route selection and engineering design. Through field investigation and testing of 25 faults in each rift valley along the Shigatse-Jilong Railway, It is found that the project crosses 10 late Pleistocene active faults, including 4 Holocene active faults, including Dingjie fault, Guojia fault, dengmoduo fault in Dingjie riftand gangpengqing fault in peikucuo rift. For Dingjie fault and Guojia fault, The south section with relatively weak activity can be selected to pass through with simple works, For dengmoduo fault with the strongest Holocene activity along the whole line, it is suggested to pass through in the form of subgrade. Due to the high risk of future earthquakes, gangpengqing fault zone should avoid passing through tunnel engineering.