基于盾构隧道斜交下穿的修正Peck公式法

Modified Peck Equation Method for Shield Tunnel Oblique Crossing Upper Railway

摘要:

在盾构隧道下穿导致的地表沉降计算中，通常需利用Peck公式理论计算盾构横断面的二维沉降.当盾构以斜交下穿时，盾构横断面不再平行于上部线路沿线方向，其沿线沉降的形式不符合正态分布，因此需要将Peck法推广到平面上任意一点的沉降计算中.综合考虑盾构坡角及隆起效应等影响因素，引入角度系数对Peck公式进行修正，使之可直接计算盾构斜交条件下地表平面上任一点的沉降，进而直接计算上部线路沿线沉降.通过有限元数值分析法进行验证，并在此基础上利用动力学仿真分析研究不同斜交角度所产生的不同沉降形式对脱轨系数及减载率的影响.

Abstract:

The Peck empirical equation is the most common method in the calculation of upper railway settlement at shield tunnel cross section. However, due to the shield tunnel oblique crossing upper railway, shield tunnel cross section is no more parallel to the upper railway direction and the settlement cannot be expressed as Gaussian distribution. The shield angle coefficients are proposed to modify the Peck equation with consideration of oblique angle, tunnel gradient and upheaval. The modified Peck equation is verified by finite element numerical analysis, which is applicable for settlement expression in different sections. And with the different settlement and composite irregularity being obtained by the modified Peck method, the rail surface irregularity is affected. With dynamic simulated analysis, the influence on derail coefficient and wheel load reduction rate is researched.