Estimating the Uplift Bearing Capacity of Belled Piers Adjacent to Sloping Ground by Numerical Modeling Based on Field Tests

Yangchun Han,Jiulong Cheng,Weifeng Zheng,Shijun Ding

doi:10.1155/2020/1647197

Abstract

In order to evaluate the uplift bearing capacity of belled piers beside slopes, a series of numerical simulations are carried out based on field tests data. First, a number of uplift loading tests of full-scale belled piers are carried out on the project site of transmission line in Anhui Province, China. Second, a slope-foundation model for numerical modeling is proposed and calibrated based on field tests data. The behavior of belled piers adjacent to slopes subject to uplift load is studied by numerical modeling. The impact of three parameters, including distance (a) from the belled pier to the crest of the slope, slope angle (β), and embedment depth (h) of the belled pier, has been investigated on the uplift capacity of the belled pier. Based on the simulation results, an attenuation coefficient (ω) is put forward for evaluating the reduction of uplift bearing capacity of the belled pier. The results show that the coefficient ω is negatively correlated with distance a and depth h, and the influence of distance a is greater than that of depth h according to the results of variance analysis, but the difference is not significant by F test. Moreover, the empirical equation between attenuation coefficient ω and three key factors a, β, and h had been presented by a series of fitting.

Highlights

Erefore, according to field test data, the numerical simulations were performed to evaluate the uplift bearing capacity of belled piers near slopes in this area
The following observations can be made: (1) e attenuation coefficient ω is negatively correlated with the distance a and the embedment depth h, as shown in Figure 11(a), Curve I and Curve II. (2) e attenuation coefficient ω is positively correlated with the slope angle β
Field tests and numerical simulations are carried out on the uplift performance of belled piers constructed in two topographical grounds. e following conclusions can be drawn: (1) For belled piers adjacent to sloping ground, the uplift load-displacement curves can be divided into three distinct stages: initial linear stage, curvilinear transition stage, and final linear stage. ese characteristics are basically consistent with that of the curves obtained from field tests of belled piers far from slopes, which indicate that the existence of slopes has no obvious effect on the shape of uplift load-displacement curves

Summary

Introduction

Erefore, according to field test data, the numerical simulations were performed to evaluate the uplift bearing capacity of belled piers near slopes in this area. At the beginning of this research, five belled piers were tested under axial uplift load on a flat ground far from slopes. Based on the data of field tests, a 3D slope-foundation model was developed, calibrated, and validated. E uplift performance of belled piers adjacent to sloping ground was simulated using the model. E simulation results were analyzed, and the attenuation coefficient ω was taken as the index to quantitatively evaluate the uplift resistance of belled pier from three aspects: the distance a between belled pier and slope, the embedment depth h of the belled pier, and the slope angle β. Based on the data of field tests, a 3D slope-foundation model was developed, calibrated, and validated. e uplift performance of belled piers adjacent to sloping ground was simulated using the model. e simulation results were analyzed, and the attenuation coefficient ω was taken as the index to quantitatively evaluate the uplift resistance of belled pier from three aspects: the distance a between belled pier and slope, the embedment depth h of the belled pier, and the slope angle β. ese results will provide sufficient theoretical and data support for the construction of transmission line foundation in mountainous and hilly areas

Methods

Results

Conclusion