紧邻围护结构超小净距盾构施工数值分析

Numerical analysis of ultra-small interval shield receiving construction near envelope structure

为研究紧邻围护结构超小净距盾构施工过程对围岩及结构的影响,以深圳市地铁14号线的宝荷站—宝龙站区间段工程为研究背景,分析在紧邻围护结构超小净距盾构施工过程中盾构-围岩-围护结构相互作用体系的受力和地表沉降规律。采用Midas GTS有限元软件对该工程盾构施工的全过程进行数值动态仿真,得到该工程盾构掘进过程中盾构-围岩-围护结构相互作用体系的变形及受力规律,并将数值模拟结果与监测结果进行对比,验证了数值模拟的准确性;在此基础上分析了土仓压力、同步注浆压力、刀盘扭矩等参数对土层及既有结构稳定性的影响,给出了施工参数建议值。研究结果表明:若依照参数建议值进行施工,产生的地表沉降等参数均在容许范围内。该研究可为类似工程提供参考。。

In order to study the influence of the construction process of the ultra-small spacing shield adjacent to the envelope structure on the surrounding rock and structure.Taking the construction of Shenzhen metro line 14 from Baohe station to Baolong station as the background,the stress law and surface settlement law of shield-surrounding rock-envelope structure interaction system were analyzed during the construction of ultra-small clear distance shield adjacent to the envelope structure.The finite element software was used to simulate the whole process of shield construction.The deformation and stress law of the interaction system were obtained during the process of shield tunneling.Compared with the monitoring results,the accuracy of numerical simulation was proved.Furthermore,the influence of parameters such as soil chamber pressure,synchronous grouting pressure and cutterhead torque on the stability of soil layer and existing structure was analyzed.And the appropriate construction parameters were proposed.The results show that,when the proposed parameters are used in construction,that the displacement parameters such as surface settlement are within the allowable range.The correctness of the research method and conclusion in this paper is verified.