基于Trapdoor试验的双线隧道地表沉降预测公式探讨  

Prediction formula for surface settlement in double-line tunnel based on trapdoor tests

作　　者：徐路畅 芮瑞[1] 张龙[1] 孙义[1] 夏元友[1] 

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070

出　　处：《岩土工程学报》2017年第8期1470-1476,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51208403);武汉理工大学国家级大学生创新创业训练计划资助项目(20151049706038)

摘　　要：城市隧道开挖引起的地层扰动不可避免。为了探讨双线隧道间相互影响以及可靠的地表沉降预测方法,利用课题组开发的多沉陷门(Multi-trapdoor)模型试验装置和钢棒相似土构建二维试验条件,通过沉陷门下沉模拟隧道开挖变形。先通过单Trapdoor试验获取表面沉降曲线,拟合得到单线隧道开挖地面沉降Peck公式参数。再进行双Trapdoor试验,利用单Trapdoor参数叠加得到双线隧道地表变形,并与双Trapdoor模型试验结果进行对比。结果反映,在埋深较大、隧道间距较小的情况下,沉降曲线较早的由双峰形态过渡到单峰形态,从而利用模型试验数据划分了两种形态的大致范围。引入了峰值修正系数和间距影响系数对叠加公式进行修正,建立了基于模型试验数据的双线隧道地表沉降叠加修正公式。The disturbance caused by the excavation of urban tunnels is inevitable. In order to investigate the mutual influence of a double-line tunnel and the reliable method for prediction of ground surface subsidence, a multi-trapdoor model test setup and analogical soil are adopted to create the two-dimensional test conditions to simulate the tunnel excavation. The deformation caused by tunnel excavation is modeled by the trapdoors sinking. First of all, three single trapdoor model tests are conducted to obtain the fitting parameters of Peck＇s formula for a single-line tunnel. Then, the fitting parameters are substituted into the superposition formula to calculate the surface settlement which is compared to the measured curves of the double-trapdoor tests. The results reflect that in the case of large buried depth and small tunnel spacing, the surface settlement will turn out to be the single-peak form earlier, then the application conditions of the two forms are determined. For the single peak, a peak value correction factor and a spacing influence correction factor are introduced to correct the Peck＇s formula, and then an equivalent prediction formula for the settlement of the double-line tunnel based on model test data is proposed.

关 键 词：双线隧道 地表沉降 PECK公式 模型试验 钢棒相似土 

分 类 号：TU470.3[建筑科学—结构工程]