Side Friction of Rock-Socketed Piles Involving Thick Sediment

This paper investigates the skin friction transfer characteristics of the rock-socketed section of a rock-socketed pile resting on thick sediment by conducting in situ core-drilling tests and static loading tests. Test results show that when using the impact hole-forming method in weakly cemented so...

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Main Authors: Tie Hang Wang, Liang Zhang, Yan Zhou Hao, Xin Jin
Format: Article
Language:English
Published: Wiley 2020-01-01
Series:Advances in Civil Engineering
Online Access:http://dx.doi.org/10.1155/2020/8882698
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author Tie Hang Wang
Liang Zhang
Yan Zhou Hao
Xin Jin
author_facet Tie Hang Wang
Liang Zhang
Yan Zhou Hao
Xin Jin
author_sort Tie Hang Wang
collection DOAJ
description This paper investigates the skin friction transfer characteristics of the rock-socketed section of a rock-socketed pile resting on thick sediment by conducting in situ core-drilling tests and static loading tests. Test results show that when using the impact hole-forming method in weakly cemented soil, a layer of sediment is deposited at the pile bottom. Due to the existence of sediment, when the load reaches a certain value, sudden and large subsidence is observed. This indicates that the end resistance does not contribute to the bearing capacity. Thus, it is not appropriate to consider both end resistance and side resistance in the existing design method of a rock-socketed pile. The bearing capacity of a single rock-socketed pile should be determined according to the side resistance of the soil layer and rock-socketed section only. Numerical analysis is performed to determine the deformation and load-carrying capacity of the pile and the distribution of friction on the sides of the rock-socketed segment. Under a given applied load, small settlement is observed when socketed thickness and rock strength are relatively large. The distribution of side friction of the socketed segment along the vertical direction shows a double-peak saddle shape. When the socketed thickness and rock strength are relatively smaller, the lower peak is higher than the upper peak, and conversely, when the socketed thickness and rock strength are relatively larger, the lower peak is smaller than the upper peak. For a given applied load on the pile top, smaller socketed thickness results in larger settlement and side friction. Due to the thick layer of sediment, the axial force of the rock-socketed segment of the pile gradually decreases along the vertical direction from the applied load on the pile top to zero at the bottom. According to the mechanical properties at different shear stages, a function is derived for the complete constitutive model for a pile-rock interface. Analytical solutions for the friction of a single pile are obtained under the conditions of failure and elasticity deformation of the surrounding rock. Its load transfer equation is derived as well. Accordingly, an equation is proposed for calculating the bearing capacity of rock-socketed piles resting on sediment at the bottom.
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institution Kabale University
issn 1687-8086
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language English
publishDate 2020-01-01
publisher Wiley
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spelling doaj-art-9470cfef899140bd90ab23022126fcc82025-02-03T01:04:28ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/88826988882698Side Friction of Rock-Socketed Piles Involving Thick SedimentTie Hang Wang0Liang Zhang1Yan Zhou Hao2Xin Jin3College of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, ChinaCollege of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, ChinaCollege of Civil Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi 710055, ChinaSchool of Civil & Architecture Engineering, Xi’an Technological University, Xi’an, Shaanxi 710021, ChinaThis paper investigates the skin friction transfer characteristics of the rock-socketed section of a rock-socketed pile resting on thick sediment by conducting in situ core-drilling tests and static loading tests. Test results show that when using the impact hole-forming method in weakly cemented soil, a layer of sediment is deposited at the pile bottom. Due to the existence of sediment, when the load reaches a certain value, sudden and large subsidence is observed. This indicates that the end resistance does not contribute to the bearing capacity. Thus, it is not appropriate to consider both end resistance and side resistance in the existing design method of a rock-socketed pile. The bearing capacity of a single rock-socketed pile should be determined according to the side resistance of the soil layer and rock-socketed section only. Numerical analysis is performed to determine the deformation and load-carrying capacity of the pile and the distribution of friction on the sides of the rock-socketed segment. Under a given applied load, small settlement is observed when socketed thickness and rock strength are relatively large. The distribution of side friction of the socketed segment along the vertical direction shows a double-peak saddle shape. When the socketed thickness and rock strength are relatively smaller, the lower peak is higher than the upper peak, and conversely, when the socketed thickness and rock strength are relatively larger, the lower peak is smaller than the upper peak. For a given applied load on the pile top, smaller socketed thickness results in larger settlement and side friction. Due to the thick layer of sediment, the axial force of the rock-socketed segment of the pile gradually decreases along the vertical direction from the applied load on the pile top to zero at the bottom. According to the mechanical properties at different shear stages, a function is derived for the complete constitutive model for a pile-rock interface. Analytical solutions for the friction of a single pile are obtained under the conditions of failure and elasticity deformation of the surrounding rock. Its load transfer equation is derived as well. Accordingly, an equation is proposed for calculating the bearing capacity of rock-socketed piles resting on sediment at the bottom.http://dx.doi.org/10.1155/2020/8882698
spellingShingle Tie Hang Wang
Liang Zhang
Yan Zhou Hao
Xin Jin
Side Friction of Rock-Socketed Piles Involving Thick Sediment
Advances in Civil Engineering
title Side Friction of Rock-Socketed Piles Involving Thick Sediment
title_full Side Friction of Rock-Socketed Piles Involving Thick Sediment
title_fullStr Side Friction of Rock-Socketed Piles Involving Thick Sediment
title_full_unstemmed Side Friction of Rock-Socketed Piles Involving Thick Sediment
title_short Side Friction of Rock-Socketed Piles Involving Thick Sediment
title_sort side friction of rock socketed piles involving thick sediment
url http://dx.doi.org/10.1155/2020/8882698
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AT liangzhang sidefrictionofrocksocketedpilesinvolvingthicksediment
AT yanzhouhao sidefrictionofrocksocketedpilesinvolvingthicksediment
AT xinjin sidefrictionofrocksocketedpilesinvolvingthicksediment