圬工与加筋土组合式挡墙离心模型试验

Centrifuge Model Tests of Behavior of Masonry and Reinforced Soil Composite Retaining Wall

摘要:

以湖北十房（十堰至房县）高速公路某处圬工与加筋土组合式挡墙为研究对象，通过土工离心模型试验技术，研究圬工与加筋土组合式挡墙的变形特性及内部土压力分布，并探讨强筋与弱筋（筋材模量）、长筋与短筋（加筋长度）以及密筋与疏筋（层间距）等参数对组合式挡墙的影响.研究发现：圬工挡墙与加筋土挡墙存在明显的相互影响，上部挡墙荷载使圬工挡墙发生内倾，这一内倾使加筋土挡墙上部水平位移进一步增大，并造成墙体底部土压力分布更不均匀；增大土工格栅模量、增加加筋长度、减小加筋间距，更有利于控制加筋土挡墙的变形；加筋土挡墙内部土压力和墙后水平土压力总体上小于理论值，且受挡墙加筋参数的影响；组合挡土结构的墙顶沉降主要发生在施工期，应加强施工质量控制，保证填土的密实度.

关键词:圬工与加筋土组合式挡墙; 离心模型试验; 变形特性; 土工格栅

Abstract:

Taking amasonryand reinforced soil composite retaining wall of Hubei Shifang(Shiyan to Fangxian) Expressway as the research object, using the geotechnical centrifuge model test, the deformation characteristics and the soil pressure distribution of the combined retaining wall was studied, and the effects of reinforcement modulus, length and vertical spacing of reinforcement on the composite retaining wall was investigated. It is found out that the lower masonry retaining wall and the upper reinforced earth retaining wall have obvious mutual influences, the introversion of masonry retaining wall occurs under the load of upper reinforced soil wall, and the introversion of masonry wall further increases the horizontal displacement of the upper part of reinforced soil retaining wall and makes the pressure distribution more uneven at the bottom. Increasing the geogrid modulus, increasing reinforced length and reducing reinforcement spacing are more conducive to the control of the deformation of reinforced soil retaining wall. The earth pressure in reinforced soil and the horizontal earth pressure behind retaining wall, which are impacted by reinforced parameters, are smaller than the theoretical value. The wall top settlement of composite retaining wall occurs mainly in the construction period, and measures should be taken to strengthen the construction quality control and ensure the compactness of soil.

Key words:masonry and reinforced soil composite retaining wall; centrifuge model test; deformation characteristics; geogrid