基于强度折减法分析管廊两侧回填土对市政道路的影响

基于土体的本构关系Mohr-Coulomb准则，并对填料压实度进行折减，运用有限元软件建立了道路-地下综合管廊结构数值模型。以长沙某综合管廊项目为实例，研究了三七灰土填料对市政道路的影响。计算结果表明:三七灰土强度折减系数FV=1.5为临界点，随着折减系数FV增大，道路沉降及应力响应明显增大；三七灰土强度参数黏聚力和内摩擦角控制值分别为13.33 kPa和22.55°，施工过程中应保证三七灰土强度不小于控制值；管廊持力层土体应力分布呈边缘大中间小的特点，其中侧墙下部应力最为集中。

Influence of Backfill of Both Sides of Utility Tunnel on Municipal Roads Based on Strength Reduction Analysis

Based on Mohr-Coulomb criterion of constitutive relation of soil body, with the compactness of filler reduced, the numerical model of road-utility tunnel structure was established with finite element software. Taking a utility tunnel works in Changsha as an example, the influence of 3:7 lime-soil on municipal road was studied. The calculation result shows that the strength reduction coefficient FV=1.5 of 3:7 lime-soil is the critical point and, as the coefficient FV increases, the road settlement and the stress response increase obviously; the control value of cohesion and internal friction angle, the strength parameters of 3:7 lime-soil, are 13.33 kPa and 22.55°, respectively, and the strength of 3:7 lime-soil shall be guaranteed not to be less than the control values in construction; the stress distribution of soil mass in the bearing layer of utility tunnel manifests large in the edge and small in the middle, wherein the stress at the lower part of side wall is mostly concentrated.