高水压地层盾构隧道管片内力计算方法分析

Analysis of internal force calculation method for shield tunnel under high hydraulic pressure

即使盾构法已成为国内外地下工程中重要的掘进工法,但由于地层岩土体的复杂性质,盾构隧道计算方法的适用性仍需探讨。以深江铁路珠江口隧道为研究对象,对比常用的修正惯用法和多铰圆环法对应的管片受荷内力受荷结果特征差异,并分析不同水压力环境对管片轴力、弯矩的影响及发展过程。结果表明:不同计算结果差异较大,修正惯用法计算结果普遍高于多铰圆环法;随着水压的增加,管片结构所受轴力增大,同时弯矩也有一定提高,但相对而言增长幅度小于轴力;而不同计算模型的结果对高水压荷载的响应存在差异;多铰圆环法的轴力对于高水压环境更为敏感;随着外环境水压的增加,管片受力以整体受压为主,同时拱脚处出现较大负弯矩,拱肩处的负弯矩区范围也减少。相关研究成果可为高水压地层盾构隧道管片设计提供参考。

Although the shield method has become an important tunneling method in underground engineering at home and abroad,the applicability of the shield tunnel calculation method still needs to be discussed because of the complex properties of rock and soil bodies.Taking the Zhujiangkou Tunnel of Shenjiang Railway as the research object,this paper compares the characteristic difference of the internal force under load corresponding to the common modified method and the multi-hinged ring method,and analyzes the influence of different water pressure environment on the axial force and bending moment of the pipe segment and its development process.The results show that there are great differences among different calculation results,and the results of modified conventional method are generally higher than those of multi-hinge ring method.With the increase of water pressure,the axial force on the segment structure increases,and the bending moment also increases to a certain extent,but the increase is less than the axial force.The results of different calculation models have different responses to high water pressure loads.The axial force of multi-hinged ring method is more sensitive to high water pressure environment.With the increase of external water pressure,the overall pressure of the segment was mainly exerted.Meanwhile,a large negative bending moment appeared at the arch foot,and the area of negative bending moment at the spinner also decreased.The relevant research results can provide reference for the segment design of high hydraulic formation shield tunnel.