不同扶壁间距的仓扶式支挡结构土压力分布

针对扶壁式挡土墙在高填方工程中支挡高度的限制，提出仓格与扶壁相结合的仓扶式新型支挡结构，考虑支挡高度、扶壁间距等因素对立板侧向土压力计算和分布的影响，进行了数值分析和离心模型试验。采用ABAQUS建立10组工况的数值模型，支挡高度分别为10，20 m，扶壁间距分别为21/100H，6/25H，27/100H，9/25H，12/25H（H为支挡结构高度），提取作用在立板上的接触应力；基于数值分析结果，制作了可调扶壁间距的支挡结构模型，分别在30g，60g离心加速度下模拟了部分工况的实际受力状况，由标定后的微型土压力盒采集数据；最后比较了实测值与理论值的差异，通过回归分析提出库仑主动土压力修正系数。研究结果表明：仓扶式支挡结构立板侧向土压力近似呈三角形分布，由于变形约束效应，在支挡结构中下部实测土压力较理论值偏大；立板侧向土压力在参照库仑理论计算时，需要考虑增大系数进行修正，10，20 m支挡高度修正系数分别为1.13~1.31和1.07~1.12；仓扶式支挡结构中的扶壁具有摩擦减压作用，通过改变扶壁间距可以有效减小立板侧向土压力。

Distribution of Earth Pressure of Warehouse-counterfort Retaining Wall with Different Counterfort Spacing

Aimed at the limitation on the supporting height of the counterfort retaining wall in a high-filled project, a new supporting structure of the warehouse and counterfort is proposed. Considering the influence of the supporting height and counterfort spacing on the calculation and distribution of lateral earth pressure, numerical analysis and centrifugal model test were carried out. The numerical model of 10 sets of working conditions was established by ABAQUS. The supporting height was 10 m and 20 m while the counterfort spacing was 21/100H, 6/25H, 27/100H, 9/25H, and 12/25H, respectively. The contact stress acting on the vertical plate was extracted. Based on the results of numerical analysis, the supporting structure model with adjustable counterfort spacing was fabricated, and the actual stress conditions of some working conditions were simulated under centrifugal acceleration of 30g and 60g respectively. The data was collected from a calibrated miniature earth pressure cell. Finally, the differences between measured and theoretical values were compared, and the Coulomb active earth pressure correction coefficient was proposed by regression analysis. The results show that the distribution of the lateral earth pressure of the warehouse-counterfort retaining structure is approximately triangular. Owing to the deformation-constrained effect, the measured earth pressure in the lower part of the retaining structure is larger than the theoretical value. When calculating the lateral earth pressure of the vertical plate with reference to the Coulomb theory, it is necessary to consider the increased correction coefficients: for wall height of 10 m and 20 m, the correction coefficients are 1.13-1.31 and 1.07-1.12 respectively. The counterfort in the warehouse-counterfort retaining structure performs the function of friction decompression. The lateral earth pressure of the vertical plate can be effectively reduced by changing the spacing of the counterfort.