衡重式加筋土路肩挡墙土工离心模型试验研究

以某山区公路旧路拓宽改造工程中新建的衡重式加筋土路肩挡土墙为原型,设计了4组模拟墙体实际位移形态的土工离心模型试验,讨论了墙后土体压实度和土中加筋对墙背土压力和路基填土变形的影响规律。试验表明：①墙后土体加筋对减小墙背承受的土压力作用随填土压实度的提高而趋于明显,主要影响区域位于上墙背的下半部分,压实度由88%增至95%会引起上墙背土压力分布由近似线性增大演化为折线型变化；②衡重台对其上覆填土存在托举效应,致使下墙背的土压力大幅减小,其影响范围约为衡重台以下约1/3下墙高度；③墙后土体加筋能提高路基填土的抗变形能力,减小因墙体侧向位移引起的填土表面下沉,对降低新旧路基间的不均匀变形效果显著。

Centrifugal model tests on shoulder balance weight retaining wall with reinforced earth

Using the new shoulder balance weight retaining wall of an old embankment widening project of a mountainous highway as the prototype, four groups of geotechnical centrifuge model tests on displacement control are designed. The influences of compactness and reinforced fill on the earth pressure on the wall and the deformation of the subgrade fill are discussed. The results show that: (1) the reinforced effect of backfill to reduce the earth pressure increases with the increasing degree of compaction. When the compactness is smaller than 95%, the reducing area of the earth pressure is mainly located in the lower half of the upper wall; (2) the equilibrator has uplift effect on its overlying soils so as to reduce the earth pressure on the lower wall, and the influence area below the equilibrator is about 1/3 height of the lower wall; (3) the reinforced soils can improve the resistance to the deformation of subgrade fill and thus reduce the settlement of surface fill caused by the lateral displacement of wall, and the uneven settlement between the old and the new subgrade is significantly mitigated.