Internal Force Analysis of Buried-boring Piles in the Yuanzishan Landslide

Hao Wang,Hongyu Qin,Zhiying Lv,Jianwei Yue,Jianwei Zhang,Chaoying Hung

doi:10.3390/app10165416

Abstract

The Yuanzishan landslide is an unstable slope in Langzhong County, located in northeast Sichuan province, China. The Guangyuan-Nanchong expressway passes through the front edge of the unstable slope, and subgrade excavation has resulted in slope deformation, which threatens the safety of the highway construction. Emergency landslide control requires reduction of the slope disturbance. This study aims to investigate the use of buried-boring piles as a potential method for emergency landslide control. A simplified calculation method was used for the design of the buried-boring piles, according to the limit equilibrium of the soil and the elastic foundation coefficient method. The measured internal force changes of the pile were compared, in order to determine the distribution coefficients of the driving force. A relationship between the driving force of the shared pile ratio and the buried depth ratios was then established. Furthermore, a variety of factors affecting the internal forces of the buried-boring pile and the lateral reaction of the soil were also studied. The results revealed that (1) there was a quadratic relationship between the driving force of the pile-shared ratio and the sliding depth ratios; (2) the maximum bending moment of the pile increased with an increase in the sliding depth ratio of the pile, following a power law relationship; (3) increasing the buried depth of the pile head reduced the influence of the pile diameter on the maximum internal forces; (4) increasing the pile diameter decreased the maximum lateral reaction of the soil. The buried-boring piles can be used in similarly unstable regions for emergency control of deforming slopes.

Highlights

During the construction of the Guangyuan–Nanchong Expressway, in the northeast Sichuan province of China, many embankment slopes were formed by excavation and dumping
Buried-boring piles were machined into holes and poured into piles, whose heads were buried under the ground surface to a certain depth
This study proposes the use of buried-boring piles for emergency control of an unstable slope, applied to the case of the Yanzishan landslide in Langzhong county, located in the northeast of the Sichuan province of China

Summary

Introduction

During the construction of the Guangyuan–Nanchong Expressway, in the northeast Sichuan province of China, many embankment slopes were formed by excavation and dumping. Several of the excavated slopes are at risk of sliding along the original surface of the Guangyuan–Nanchong. Emergency control measures are needed to reduce disturbance to the slope [1]. Buried-boring piles were machined into holes and poured into piles, whose heads were buried under the ground surface to a certain depth. Buried-boring piles result in less disturbance to the slope and are used for emergency control of unstable slopes. Many scholars have investigated the mechanism of the pile–soil interaction under lateral loads

Objectives

Methods

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Discussion

Conclusion