Numerical Simulation Study on the Influence of Different Factors on the Uplift Bearing Capacity of Root Piles, Straight-Shaft Piles, and Pedestal Piles

Junpeng Zhou,Xuefeng Huang,Xueming Wang,Jun Yuan,Song-He Wang

doi:10.1155/2020/8853131

Abstract

Root pile (hereafter called RP), which is a promising new type of noncircular cross-section-shaped pile and meets the requirements of the development of the uplift pile, was introduced for promotion. On the basis of validation of experimental and numerical results, finite element models were established to study the influence of the arrangement of roots and dimension parameters on the uplift bearing capacity and the economy of RP compared with that of the straight-shaft pile and pedestal pile (hereafter called SP and PP, respectively). The results show that the uplift bearing capacity of RP is higher than that of SP and PP, and the longer the pile length is, the more the bearing capacity of RP would increase compared with that of SP and PP. In order to further improve the bearing capacity of RP, the bearing mechanism of the root was analysed, and the suggested values of root size and spacing of layers are given. In addition, the most economical way to increase pile bearing capacity is to increase pile length rather than increasing pile diameter.

Highlights

With the development of infrastructure construction, the development of piles is exposed to a series of challenges, including higher bearing capacity and less material consumption
Discussion on the Influence of Pile Length and Diameter and Hollow Sections. e comparison of the influence of pile length and diameter on the bearing capacity of different pile types is shown in Figure 19, in which the number of root layers of RP length ranging from 5 m to 25 m is 2–6, respectively, the length of the root is half of the pile diameter, and the annular spacing of roots is between 0.4 and 0.5 m
The spacing of root layers is independent of pile length and diameter and should not be less than 2.4 m

Summary

Introduction

With the development of infrastructure construction, the development of piles is exposed to a series of challenges, including higher bearing capacity and less material consumption. RP is a new type of pile and put forward by Yin [11] firstly, as shown, which is formed by grafting prefabricated roots onto SP. E mechanism of RP is including side friction of the pile shaft and cantilever action of prefabricated roots, and RP could improve bearing capacity effectively. E compressive bearing capacity of root caissons and the optimal distribution of roots were investigated by Gong et al [12] through field loading tests and Yin et al [13] through numerical simulation, respectively, and their research RP was mostly used as a compressive bearing foundation since its advent, and investigation and application on the uplift bearing behaviour of RP is rare so that its uplift bearing capacity was often ignored by researchers. e compressive bearing capacity of root caissons and the optimal distribution of roots were investigated by Gong et al [12] through field loading tests and Yin et al [13] through numerical simulation, respectively, and their research

Methods

Results

Discussion

Conclusion