盾构下穿高铁路基变形规律模型试验研究  

Model test on the deformation law of shield tunnel underpassing high speed railway roadbed

作　　者：刘勇 周怡晟[1] 索晓明 樊浩博 曹毅泽 杜志田 LIU Yong;ZHOU Yi-sheng;SUO Xiao-ming;FAN Hao-bo;CAO Yi-ze;DUZhi-tian(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China;China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,河北石家庄050043 [3]中国铁路设计集团有限公司,天津300308

出　　处：《岩土力学》2023年第4期941-951,共11页Rock and Soil Mechanics

基　　金：国铁集团重点课题(No.N2020G009);国家自然科学基金青年基金(No.52108378);青年人才托举工程(No.2021QNRC001)。

摘　　要：为了探究盾构下穿施工对高铁路基U型槽结构和地层的变形影响规律,以拟建的石家庄市轨道交通4号线下穿京石高速铁路路基为工程背景,基于几何相似比配制了地层和结构模型试验材料,设计了试验监测系统,采用φ1 200 mm小型盾构机进行了盾构隧洞顶距路基管桩底不同距离的2组室内模型试验。结果表明:随着距离盾构隧道拱顶距离的增大,地层沉降减小,盾构施工对地层的影响范围约为2倍洞径,显著影响区为1倍洞径;随着埋深的增大,盾构施工引起结构下方地层的沉降减小,距盾构隧道顶距离分别为0.5倍洞径和1倍洞径时沉降最大差值为10%;U型槽结构与相邻地层间产生脱空,盾尾脱出阶段发生的地层沉降占比大于74%。建议管片拼装完成后采用保水性好且有一定早期强度的注浆填充材料,以控制沉降变形,同时进行地层深孔注浆,及时充填松动地层孔隙,增加地层密实度。The purpose of this paper is to investigate the effect of shield underpass construction on the deformation of the U-shaped trough structure and stratum of the high speed railway roadbed. The proposed Shijiazhuang rail transit line No.4 underpassing the Beijing-Shijiazhuang high-speed railway roadbed is selected as the engineering background. The stratum and structural model test materials are formulated based on the geometric similarity ratio, and the test monitoring system is designed. A φ1 200 mm small shield is employed to carry out 2 sets of laboratory model tests for different distances from the vault of the shield tunnel to the bottom of pile in the roadbed. The results show that: with the increase of the distance from the shield tunnel vault, the settlement of the strata decreases, the influence range of the shield construction on the strata is about 2 times of the diameter of the tunnel, and the significant influence range is one time of the diameter of the tunnel;with the increase of the burial depth, the settlement of the strata under the structure caused by the shield construction decreases, and the maximum difference of settlement is 10% at the distance of 0.5 and 1.0times of the diameter of the tunnel respectively from the shield tunnel vault;a dehiscence occurs between the U-shaped trough and the adjacent strata, and the percentage of settlement of the strata occurring during the shield tail release phase is greater than 74%. It is recommended to use grout filling material with good water retention and certain early strength after the completion of segment assembly to control the settlement deformation. Meanwhile, deep hole grouting should be carried out to timely fill loose ground pores so as to increase the compactness.

关 键 词：盾构隧道 下穿高铁路基 地层变形 模型试验 

分 类 号：TU475[建筑科学—结构工程]