为确定涵侧填土对高填方涵洞地基承载力的提高作用,根据相似原理设计高填方涵洞模型试验,模拟不同涵侧填土高时涵洞地基受荷破坏的过程,绘制荷载-沉降曲线得到极限荷载;讨论使用经验公式和JTG D 63—2007《公路桥涵地基与基础设计规范》的计算结果与试验结果的差值;选取图们至珲春高速公路桩号为RK365+510处的高填方涵洞作为试验涵洞,在涵洞底部埋设沉降观测点测量基底沉降值和沉降差。结果表明:侧填荷载对地基承载力的提高十分显著,且提高幅度为非线性,先从18.4%增加到36.83%,然后减小到8.91%;计算承载力时不仅要考虑选取合适的计算公式,还应考虑不同试验方法所提供的计算参数的影响;现场测试的涵洞基底最大沉降值符合规范的要求。
In a semi-discretized Euler-Bernoulli beam equa- tion, the non-nearest neighboring interaction and large span of temporal scales for wave propagations pose challenges to the effectiveness and stability for artificial boundary treat- ments. With the discrete equation regarded as an atomic lattice with a three-atom potential, two accurate artificial boundary conditions are first derived here. Reflection co- efficient and numerical tests illustrate the capability of the proposed methods. In particular, the time history treatment gives an exact boundary condition, yet with sensitivity to nu- merical implementations. The ALEX （almost EXact） bound- ary condition is numerically more effective.
