盖板涵洞采用废轮胎条轻质土减荷试验

Research on the Role of Reinforced Soil with Tires to Reduce the Vertical Earth Pressure above the Roof-Culvert

目的采用废轮胎条混合轻质土作为涵顶回填材料来解决涵顶土应力集中的问题,并进一步探究涵顶土应力分布规律.方法以甘肃省天定高速公路涵顶回填废轮胎条混合轻质土工程为依托,以现场原型试验为研究手段,结合理论分析,系统研究了回填该材料对涵顶竖向土应力分布规律的影响.结果涵顶未铺设废轮胎条混合轻质土时,涵顶竖向土应力集中现象明显,且土应力沿涵顶横向呈开口向上的抛物线形式分布,涵顶中点处土应力值最小,边缘处最大;在涵顶铺设一定厚度的废轮胎条混合轻质土后,涵顶竖向土应力有明显地减小,且受涵顶土应力分布规律的影响.结论轻质土具有明显的减荷作用且减荷作用具有区域性,应力集中最大的涵顶边缘处减荷效果最佳,并推出类似工况的涵顶土应力计算经验公式.

The research aims to solve the earth pressure concentrated on the roof-culvert with reinforced soil with tires, and explore the law of the earth pressure on the roof-culvert deeply. Based on the backfilling program conducted on the roof-culvert of Tianshui-dingxi highway in Dingxi City of Gansu Province, using the on-site field test research combined the theoretical analysis, the research studied the rules of the vertical earth pressure above the roof-culvert reinforced soil with tire shreds. The results showed that vertical earth pressure concentration was obvious when the roof-culvert was without the reinforced soil with tires and the earth pressure alone the roof-culvert had the distribution as an opening up parabola with the minimum value in the middle and maximum value at the edge;using the reinforced soil which was soil mixed with tires as the off-loading materials could off-load the earth pressure above the roof-culvert. This reinforced soil has the off- loading function and this function is regional. It works best on the edge. These monitoring results can be used as a reference for future study and design.