台涵背回填料性质对瑞雷波传播特性的影响

Effect of Property of Material for Backfill behind Abutment and Culvert on Raleigh Wave Propagation

针对瞬态瑞雷波法用于检测道路工程台涵背回填质量这一问题,通过现场试验结合有限元方法,分析台涵墙背回填中土层深度、填料含水率、颗粒级配、边界条件等因素对瑞雷波传播特性的影响,结果表明:考虑土层深度,得到的探测结果稍优于不考虑深度影响的情况;填料细粒含量多,含水率变化对波速影响较大,而对于巨粒土和砾类土而言,含水率变化对波速影响小;土体级配良好,采集数据信噪比高,比较常见的几种填料,在砂类土中获得的信号质量最好;路基边界对测试结果影响较小,但是如果台涵墙背倾斜,则需结合工程实际考虑测线下方墙体的影响,防止对结果误判。

Focusing on the problem of using transient Rayleigh wave method to test quality of backfill behind abutment and culvert in road engineering,field test and FEM are employed to analyse the effects of soil depth,water content of fill,granule gradation and boundary condition on Raleigh wave propagation property in backfill behind abutment,culvert and wall. The result indicates that（ 1） the detection test result by considering soil depth are slightly superior to the test result without considering soil depth;（ 2） for the fill has more fine grain,the change of water content influences wave velocity greater,while for over coarse grained soil and gravelly soil,the change of water content has less impact on wave velocity;（ 3） comparing several common fills,the data gathered from well graded soil has a higher signal-noise ratio,and the signal quality gathered from sandy soil is best;（ 4） boundary condition of subgrade has little influence on test result,but if the wall back of abutment or culvert is oblique,the influence on the wall under the measuring line should be considered based on engineering practice to avoid misjudgment.