轨道湿陷性黄土现场浸水试验及处置方案比选研究

Study on Field Flooding Test and Comparison and Selection of Disposal Schemes of Track Collapsible Loess

鉴于湿陷性黄土在轨道工程中的影响研究较为缺乏,本文以太原地铁1号线土建7标为工程依托,开展黄土湿陷性浸水现场试验,在总结分析相关工程经验的基础上提出合理处置方案,并采用ANSYS对所选方案进行数值模拟验证。研究结果表明:工程场地为Ⅱ级中等湿陷场地且无剩余湿陷量;经比选,针对车站,部分采用整体下压3 m,主体底板下黄土层采用三七灰土换填,附属基坑采用坑内灰土挤密桩处理,过街通道采用暗挖洞内微型桩处理;针对区间隧道,盾构工法洞内注硅化浆液处理(单液硅化法)为最优处置方案;数值计算结果表明微型桩处理方案可以满足要求。所得结论对今后类似工程设计与施工具有重要的参考和借鉴价值。

In view of the lack of research on the influence of collapsible loess in track engineering,based on the project of civil engineering bid 7 of Taiyuan Metro Line 1,this paper carries out loess collapsible flooding field test,puts forward a reasonable treatment scheme on the basis of summarizing and analyzing relevant engineering experience,and uses ANSYS to verify the selected scheme by numerical simulation.The research results show that the engineering site is a gradeⅡmedium collapsible site with no residual collapsibility;after comparison and selection,for the station,part of the whole pressure is 3 m,the loess layer under the main floor is replaced by Panax notoginseng lime-soil,and the auxiliary foundation pit is treated with lime-soil compaction pile in the pit.The street passage is treated with micro piles in the underground excavation tunnel;for the interval tunnel,the silicification slurry treatment(single liquid silicification method)is the best disposal scheme.The numerical results show that the treatment scheme of micro-pile can meet the requirements.The conclusion has important reference value for the design and construction of similar projects in the future.