Abstract:Research purposes: Lhasa-Xigaze Railway travels across Yarlung Zangbo suture zone with complex geological conditions. Especially, due to the Yarlung Zangbo valley area traverses Damxung-Yangbajain-Nimu-Duoqingcuo geothermal active belt, the complex terrain and more development faults lead to the geological problems, such as geothermy, rockfall and sandstorm, which are developed along the line. According to studying the cause and distribution range of the geological problems, the rational basis for line and design scheme selection can be obtained.
Research conclusions:(1) Due to the Yarlung Zangbo section of the railway traverses Damxung-Yangbajain-Nimu-Duoqingcuo geothermal active belt, the geothermy is developed in this region. According to the geo-temperature test results, the main part of the tunnel in Yarlung Zangbo valley area was located in the low temperature zone, and a little part in medium-high temperature zone. The magmatic melt at about 6 to 8km below the ground surface is the main heat source. And the deep and large faults have provided the well storage and movement spaces for the melt. (2) The geological structure, neotectonic movement, stratum lithology and topographic are the main factors that affect the development of rockfall on both sides of the valley. Besides, there are external factors influenced the development and they are meteorological condition, unloading action and weathering action. (3) The sandstorm areas are mainly located along the wide valley of Lhasa River and Yarlung Zangbo River and Jiqiong pass. The types includes shifting dune, semi-fixed sand dune, barchan dune, longitudinal dune, semi-fixed sand land and drifting sand land and so on. The formation and distribution are controlled by the special climate, environment and human activity. (4) The research conclusions have been successfully applied in the geological route selection and engineering design and can supply references for similar engineering construction.
1]廖志杰. 西藏地热活动的背景及热源问题的讨论[J]. 北京大学学报(自然科学版),1982(1):71-77.
Liao Zhijie. Discussion on the Geothermal Activity Background and Heat Resources in Tibet[J]. Acta Scientiarum Naturalium Universitatis Pekinensis, 1982(1):71-77.
[2]鲁连仲.西藏地热活动的地质背景分析[J]. 地球科学(中国地质大学学报), 1989(S1):53-59.
Lu Lianzhong. Analysis the Geology Background of the Geothermal Activity in Tibet[J]. Earth Science(Journal of China University of Geosciences), 1989(S1):53-59.
[3]西藏地矿局地热地质大队. 西藏自治区那曲-尼木地热带地热调查报告[R]. 拉萨:西藏地矿局地热地质大队,1991.
Geothermal and Geology Group of the Bureau of Geological Exploration & Development of Tibet Autonomous Region. The Geothermal Exploration Report of the Nagqu-Nimu Geothermal Region[R]. Lhasa: Geothermal and Geology Group of the Bureau of Geological Exploration & Development of Tibet Autonomous Region,1991.
[4]金炯,董光荣,邵立业,等. 西藏土地风沙化问题的研究[J]. 地理研究,1994(1):60-68.
Jin Jiong, Dong Guangrong, Shao Liye,etc. Study on the Wind-sand Impacted Lands in Tibet Autonomous Region[J]. Geographical Research,1994(1):60-68.
[5]李顺平,蒋富强,薛春晓,等. 青藏铁路格拉段沙害现场调查及防治研究[J]. 铁道工程学报,2014(5):1-5.
Li Shunping, Jiang Fuqiang, Xue Chunxiao, etc. Field Investigation of Sand Disaster and Prevention Research on the Golmud-Lhasa Section of Qinghai-Tibet Railway[J]. Journal of Railway Engineering Society, 2014(5):1-5.
[6]梁伯仁. 宝成铁路略阳至广元段危岩落石剖析[J]. 铁道工程学报,1989(1):114-118.
Liang Boren. The Study of Rockfall along Lueyang to Guangyuan of Baoji to Chendu Railway[J]. Journal of Railway Engineering Society, 1989(1):114-118.
[7]王进华. 青藏铁路堆龙曲峡谷区危岩落石的形成机理及其防治[J]. 铁道勘察,2004(6):73-75.
Wang Jinhua. The Deformation Mechanism and Prevention of Rockfall in Duilongqu Valley Area, Qinghai-Tibet Railway[J]. Railway Investigation and Surveying,2004(6):73-75.
[8]翟继伟. 辛泰线危岩落石整治[J]. 路基工程,2012(3):189-190.
Zhai Jiwei. Treatment on Dangerous Rock and Rockfall along Linzi-Taian Railway Line [J]. Subgrade Engineering, 2012(3):189-190