刚性地基与柔性地基下减载式涵洞受力特性
Mechanical Characteristics of Load Reduction Culvert under Rigid Foundation and Flexible Foundation

减载式涵洞通过改变涵–土体系应力的传递路径来减小涵顶土压力，达到减载的效果，但是地基的刚度对减载式涵洞不同位置受力特性的影响还未知。本文通过模型试验的方法对该新型减载式涵洞在柔性地基和刚性地基下的荷载传递规律进行了对比研究，得到了地基的刚度对减载式涵洞的受力特性的影响。试验结果表明：刚性地基与柔性地基下减载式涵洞涵顶土压力与涵侧水平土压力差别较小，而涵底土压力差别较大。地基的刚度对减载式涵洞的涵顶土压力和涵侧水平土压力的影响相对较小，但不是完全没有影响；地基的刚度对涵底土压力影响较大。刚性地基下涵底中间土压力远大于柔性地基下涵底中间土压力，且二者的差距随着填土高度的增加而逐渐增大。柔性地基下涵底侧边土压力明显大于刚性地基下涵底侧边土压力，且二者的差距随着填土高度的增加而先增大后减小。
The load reduction culvert reduces the soil pressure at the top of the culvert by changing the transfer path of the culvert-soil system to achieve the effect of load reduction, but the influence of the stiffness of the foundation on the force characteristics of the load reduction culvert at different locations is unknown. In this paper, the load transfer law of the new load reduction culvert under flexible foundation and rigid foundation is studied by model test method, and the influence of the stiffness of the foundation on the force characteristics of the load reduction culvert is obtained. The test results show that the difference between the soil pressure at the top of the culvert and the horizontal soil pressure at the side of the culvert under the rigid foundation and the flexible foundation is small, while the difference between the soil pressure at the bottom of the culvert is large. The stiffness of foundation has relatively little influence on the earth pressure at the top and the horizontal earth pressure at the side of the culvert, but it is not completely irrelevant. The stiffness of foundation has great influence on the subsoil pressure of culvert. The earth pressure in the middle of the culvert under the rigid foundation is much larger than that of the soft foundation, and the difference between them increases with the increase of the fill height. The soil pressure at the bottom of the soft foundation is obviously greater than that at the bottom of the rigid foundation, and the difference between the two increases first and then decreases with the increase of the filling height.