Numerical parametric study on behavior of bearing reinforcement earth walls with different backfill material properties

Abstract

This paper presents a numerical parametric study on behavior of bearing reinforcement earth (BRE) walls with different backfill properties using the finite-element method software PLAXIS 2D. The primary objective of this study was to improve the understanding of bearing stress, settlement, lateral earth pressure, and horizontal wall movement of BRE walls with different backfill materials. The second objective of this study was to evaluate the effects of various soil-structure interactions, foundations, and stiffness of reinforcements on horizontal wall deformations. The backfill materials consisted of four types of soil, which were mixtures of silty clay and sand at different fine contents of 2, 20, 40, and 80% by dry weight. The model parameters for the numerical simulation were obtained from the conventional laboratory tests and back-calculated from the laboratory pullout tests of the bearing reinforcement. The geotextile elements were used to model the bearing reinforcements by converting the contribution of friction and bearing resistances to the equivalent friction resistance, which was represented by the soil-bearing reinforcement interaction ratio, R inter . The values of R inter decreased following a polynomial function as an increase of fine content in the ranges of 0.65-0.38 and 0.75-0.40 for the numbers of transverse members, n = 2 and 3, respectively. The simulated bearing stress in the reinforced zone decreased from the front to the back of the wall because the BRE wall behaved as a rigid body built on the relatively firm foundation retaining the unreinforced backfill. The foundation settlement decreased from the facing of the wall to the unreinforced zone for all backfill properties due to the slight rotation of the wall. The relationship between the maximum horizontal wall movement and the fine content can be expressed by a polynomial function. The maximum horizontal wall movement significantly increased as the fine content increased. The excessive movement was realized when the fine content was greater than 45%. The increase of the fine content moved the location of the maximum wall movement higher up from the mid to the top of the wall. A numerical parametric study was conducted to investigate the soil-structure interaction, foundation, and stiffness of reinforcement. These parameters affected the horizontal wall deformation, which is especially important for serviceability of BRE walls. The knowledge gained from this study provides a preliminary guideline in predicting the behavior of BRE walls and may be used to investigate other BRE walls with different wall heights and features of bearing reinforcements.

An analytical solution for geotextile-wrapped soil based on insights from DEM analysis

“…Geosynthetics are cost-effective and environmentally friendly geomaterials that can be designed with great flexibility to reinforce geostructures. Planar geosynthetic sheets, such as geotextiles and geogrids, are commonly embedded horizontally within retaining walls (Rowe and Skinner, 2001;Sukmak et al, 2016) and subgrades (Giroud and Han, 2004;Chen et al, 2015). The 2D circumferentially closed cellular forms of geosynthetic reinforcements, e.g., geosynthetic encasements, are installed around cylindrical granular stone columns in soft foundations to improve the lateral support and restrain dilation (Pulko et al, 2011;Wu and Hong, 2014;Geng et al, 2017).…”

Numerical assessment of geocell-reinforced pavement performance subjected to cyclic loading conditions

“…The behaviors of the base, subbase, and subgrade soils were represented using the Mohr-Coulomb constitutive model. Several researchers have used similar constitutive models to simulate problems involving cyclic loading [12][13][14][15]. The geotextile and geocell layers were modeled as linear elastic elements.…”

Mô hình số phân tích ứng xử của tường chắn đất có cốt sử dụng các loại vật liệu đất đắp tại chỗ khác nhau

“…Ngày nay kết cấu tường chắn đất gia cố bằng lưới địa kỹ thuật (GRSW) ngày càng được áp dụng rộng rãi trong các dự án công trình giao thông, các công trình gia cố, ổn định taluy đường, mố cầu. So với giải pháp tường chắn bê tông cốt thép trọng lực hoặc bán trọng lực truyền thống, giải pháp này có nhiều ưu điểm nổi bật như có khả năng chịu tải trọng động tốt, giảm ảnh hưởng lún chênh lệch ở đỉnh tường, thời gian thi công nhanh, chi phí thi công thấp do tận dụng được các nguồn lực tại chỗ, thân thiện môi trường và có khả năng cải thiện tính thẩm mỹ cao [1,2]. Một kết cấu GRS thường bao gồm bốn thành phần chính: đất đắp, lưới địa kỹ thuật, bề mặt tường và hệ thống thoát nước sau tường.…”