新型速凝材料注浆加固富水破碎带机制分析

富水断层破碎带是治理难度较大的不良地质体,针对南京地铁建设中基坑大面积涌水、支护结构沉降变形及常规注浆材料防渗加固效果有限的问题,基于水文地质和高密度电法,分析基坑涌水的渗流状态;通过室内试验测定新型速凝浆液的初终凝时间、结石体强度及结石率,得出该材料具有较好的可注性和可行性;采用COMSOL数值软件,联合仿真模拟了富水破碎带注浆加固过程,对比分析注浆前后基坑渗流规律,并基于此开展了现场注浆试验;利用地质雷达和压水试验对注浆效果进行验证,结果显示该新型速凝材料对富水破碎带加固效果良好,COMSOL联合仿真对注浆设计有科学的指导性。

Analysis on Mechanism of Reinforcement of Water-rich Fractured Zone by Means of Grouting with New Type of Accelerator

Water rich fractured zone always results in problems in construction. During the construction of a foundation pit of Nanjing Metro, problems, such as serious water inflow, settlement and deformation of support structure and limited grouting effect by traditional grouting materials, occur. In the paper, the water seepage of the foundation pit is analyzed by means of hydrogeology method and high intensity resistivity method. The grouting reinforcement process of the water rich fractured zone is co simulated by means of COMSOL numerical software, comparison and contrast is made between the water seepage pattern before grouting and that after grouting, and site grouting test is carried out. The grouting effect is testified by means of geology detection radar and packer permeability test. The results show that good grouting reinforcement effect has been achieved by using new types of accelerators, and COMSOL co simulation method can provide guidance for grout design. 