基坑上跨既有盾构隧道坑底土体加固方式探究  

Study on reinforcement method for foundation pit of existing shield tunnel under foundation pit

作　　者：施成华[1] 李翔 雷明锋[1] 彭立敏[1] SHI Chenghua;LI Xiang;LEI Mingfeng;PENG Limin(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《铁道科学与工程学报》2020年第5期1147-1155,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51778636)。

摘　　要：基于非线性接触理论,建立三维非连续地铁隧道模型。考虑管片接头之间、管片衬砌与围岩之间、螺栓与螺栓孔之间的相互作用,以及基坑施工全过程的影响,对基底纵向加固、横向抽条加固和格栅加固3种不同形式的加固措施在控制隧道整体竖向变形、管片接头混凝土应力、螺栓内力方面进行对比分析。研究结果表明:格栅加固效果最为理想。以此模型为基础,进一步研究隧道与基底加固区夹角α与隧道隆起变形、接头混凝土应力的关系,得到最优隧道与基底加固区夹角应为2倍土体内摩擦角与45°之间。Based on the nonlinear contact theory, a three-dimensional discontinuous subway tunnel model was established, which considered the interaction between segment joints, interaction between the segment and the surrounding rocks, and the interaction between the bolt and the bolt hole as well as the influence of the whole process of excavation construction. Contrast and analysis were made on controlling the whole vertical deformation of tunnel, the stress of segment joint concrete and the internal force of bolts based on three different reinforcement measures, i.e. longitudinal reinforcement, transverse strip reinforcement and grid reinforcement. The results show that the grid reinforcement effect is the optimal solution. On the basis of this model, the relationship between the width and diffusive angle of grille reinforcement and the deformation of tunnel uplift and the stress of joint concrete is further studied. The optimum diffusion angle should be between the 2 times the friction angle in the soil and 45 degrees.

关 键 词：盾构隧道 共线 管片接头模型 格栅加固 隧道与基底加固区夹角 

分 类 号：TU-47[建筑科学]