公路路基地基承载力的离心模型试验与分析

公路路基由于基底的柔性和荷载分布为梯形,路基地基的破坏模式和确定方法与刚性基础地基有所差异,对公路路基地基承载力的研究具有重要的理论意义和实用价值。通过柔性条形基础、梯形路基以及模拟沟谷地形的柔性条形基础等3组离心模型试验,对公路路基地基的破坏机制和极限承载力进行了研究,并采用关联流动的Mohr-Coulomb内切圆屈服准则对试验结果进行了数值模拟和对比分析,研究结果表明,公路路基地基由于基底的柔性和较高的离心加速度,很难产生理想的整体剪切破坏形式;与刚柔性条形基础相比,梯形路基作用下的基底中心点沉降更大;沟谷地形对柔性条形基础基底中心点的沉降有一定的影响,但并不明显影响地基极限承载力。

Centrifugal test and analysis of bearing capacity of foundation under highway subgrade

Because of the flexible interface and trapezoidal load, the failure modes and determination method of foundation under highway subgrade are different to the rigid foundation; so the study about bearing capacity of foundation under highway subgrade has valuable significance in theoretical research and practical engineering. Through centrifugal test of bearing capacity under different conditions such as flexible strip foundation, trapezoidal subgrade and flexible strip foundation of valley, bearing capacity of foundation under highway subgrade are studied; numerical simulation based on Mohr-Coulomb inside-tangent circle yield criterion are applied. Results show that it is difficult for subsoil under highway subgrade to come into being integer shear failure because of flexible foundation and rather high centrifugal acceleration; compared with rigid and flexible strip foundation, the central point under trapezoidal loading has greater displacement; the displacement of central point under flexible strip foundation are influenced by the valley terrain; ultimate bearing capacity is not obviously changed.