联络通道冻结法设计关键要点及数值模拟

Key Points and Numerical Simulation of Freezing Method Design for Connecting Passage

联络通道冻结法以盐水为媒介对岩土体进行冻结,达到满足安全要求的冻结壁厚度。其设计的合理性非常重要,设计关键要点包括设计思路、周边环境及工程地质条件、冻结壁厚度、冻结壁平均温度及交界面温度、单孔盐水流量、盐水温度控制、积极冻结时间等。基于此,以某项目为例,确定该联络通道冻结壁厚度2.5 m,平均温度-10℃,通过数值模拟的方法,对冻结壁的强度和变形进行计算分析,结果表明:冻结壁最大压应力为1.5 MPa,最大拉应力0.3 MPa,最大剪应力0.6 MPa,抗压、抗拉和抗剪的安全系数分别为2.4、6.7和2.5,冻结壁最大移位15.9 mm,满足冻结壁强度和变形要求。该项目的顺利实施表明了该工程设计和数值模拟结果是合理的。

The connecting passage freezing method uses salt water as the medium to freeze the rock and soil,achieving a frozen wall thickness that meets safety requirements.The rationality of the freezing method design for the connecting passage is very important.The key points of the freezing method design includ design ideas,surrounding environment and engineering geological conditions,thickness of the freezing wall,average temperature of the freezing wall and interface temperature,single hole salt water flow rate,salt water temperature control,active freezing time,etc.Based on this,taking a certain project as an example,the thickness of the frozen wall of the connecting passage was determined to be 2.5 m,with an average temperature of-10℃.Through numerical simulation,the strength and deformation of the frozen wall were calculated and analyzed.The results showed that the maximum compressive stress of the frozen wall was 1.5 MPa,the maximum tensile stress was 0.3 MPa,the maximum shear stress was 0.6 MPa,and the safety factors for compression,tension,and shear were 2.4,6.7 and 2.5,respectively,the maximum displacement of the frozen wall was 15.9 mm.The results meet the strength and deformation requirements of the frozen wall.The smooth implementation of this project indicates that the engineering design and numerical simulation results are reasonable.