桩板式挡土墙土压力分布特征的试验研究和数值分析

Study of the Soil Pressure Distribution Characteristics and Soil Arch Effects for Pile-plate Retaining Walls

为深入揭示抗滑桩间距和桩间挡板布设位置对桩板式挡土墙土压力分布特征的影响,拟首先采用室内模型试验,研究不同桩间距与不同置板工况下桩板墙的水平受荷特性,并结合ABAQUS数值计算软件对模型试验进行对比验证,藉此探究抗滑桩间距对土拱效应影响的一般规律。结果表明:在不同桩间距下,桩前置板桩背侧土压力所达到的峰值均大于桩后置板,且同一高度下桩前置板土压力均略高于桩后置板。同时,随着桩间距的增加,桩背侧承受更多由土拱效应传递的推力荷载,致使桩间挡板位移随之增大,填土内土压力峰值向土体深处与远离桩背方向发展。在一定桩间距范围内,桩间距越大抗滑桩所承担的土压力越多,越有利于挡土板后土拱效应的发挥,但需预防桩间填土的局部坍塌破坏。采用数值模拟弥补室内模型试验监测数据的方法不足以全面获取模型内的应力应变特性。数值计算结果发现:土拱的拱矢高度与桩间距呈正相关,在一定范围内,桩间距的增加有利于土拱效应的发挥。

In order to reveal the influence of the anti-slip pile spacing and the location of the inter-pile baffle on the support effect of cantilevered pile-plate retaining wall,the paper intends to study the horizontal load characteristics of cantilevered pile-plate retaining wall under different pile spacing and different slab placement conditions by using indoor model tests,and to compare and verify the model tests with ABAQUS numerical calculation software,which investigates the general rule of the influence of anti-slip pile spacing on soil arch effect.The results show that for different pile spacing,the peak soil pressure on the back side of the pile-front plate is higher than that on the back side of the pile,and the soil pressure on the pile-front plate is slightly higher than that on the back side of the pile at the same height.At the same time,with the increase of pile spacing,the back side of the pile is subjected to more thrust load transmitted by the soil arch effect,resulting in the increase of the displacement of the inter-pile baffle,and the peak soil pressure in the fill develops deeper and farther from the back of the pile.Within a certain range of pile spacing,the larger the pile spacing,the more soil pressure the anti-slip pile bears,and the more beneficial to the soil arch effect behind the baffle,but it is necessary to prevent the local collapse of the fill between the piles.Further,numerical simulations were used to compensate for the inadequacy of indoor model test monitoring data to fully obtain the stress-strain characteristics within the model.The numerical calculation results found that the arch vector height of the soil arch is positively correlated with the pile spacing,and in a certain range,the increase of the pile spacing is beneficial to the arch effect.