|Table of Contents|

Study on bearing characteristics of reinforced cage expanded head anchor rods in gravelly clay strata(PDF)

《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]

Issue:
2025年03期
Page:
172-182
Research Field:
岩土工程
Publishing date:

Info

Title:
Study on bearing characteristics of reinforced cage expanded head anchor rods in gravelly clay strata
Author(s):
ZHANG Xingui1;  TIAN Yingzhi1;  HAN Wei2;  ZHANG Yidan2;  PAN Zhengyu3
(1. School of Civil Engineering and Architecture, Guangxi University, Nanning 530004, Guangxi, China; 2. Guangxi University Design Institute Co., Ltd., Nanning 530007, Guangxi, China; 3. Guangxi Transportation Science and Technology Group Co., Ltd., Nanning 530007, Guangxi, China)
Keywords:
reinforced cage expanded head anchor rod;  gravelly clay;  bearing characteristic;  lateral pressure coefficient;  plastic deformation
PACS:
TU473
DOI:
10.19815/j.jace.2023.09048
Abstract:
In order to investigate the bearing performance of reinforced cage expanded head anchor rods in gravelly clay strata, the field destructive tests were conducted on six anchor rods with different expanded head sizes, expanded head lengths and total lengths to determine the calculation method of the ultimate pullout force. Based on the results of the destructive tests, the size of reinforced cage expanded head anti-floating anchor rod of engineering project was designed, and the acceptance tests were carried out on six reinforced cage expanded head anti-floating anchor rods with the same design parameters. A three-dimensional finite element model was established, and the rationality of the model was verified by fitting and comparing the load-displacement curve and the ultimate pullout force of the model with the field test results. The load transfer mechanism and load sharing ratio of reinforced cage expanded head anchor rods were studied and the failure mechanisms were analyzed. The results show that compared to anchor rods with the same diameter, the reinforced cage expanded head anchor rods exhibit significantly improved bearing capacity and deformation control ability. For non-prestressed reinforced cage expanded head anchor rods in gravelly clay strata, a lateral pressure coefficient of 0.8Ka(Ka is the active soil pressure coefficient of soil at the front end of expanded head anchor rod)is found to be reasonable. In gravelly clay strata, the plastic deformation of reinforced cage expanded head anchor rods account for a significant proportion, with the ratio of plastic displacement to total displacement reaching 49.81% to 55.01% when the tensile load reached 0.6 times of the ultimate pullout force. The friction resistance in the ordinary section, end resistance of the expanded head and friction resistance in the expanded section account for 44.2%, 12.2%, 43.6% of the anchor rod's ultimate bearing capacity, respectively. The lateral friction resistance of expanded head anchor rod shows an overall trend of increasing-decreasing-increasing-decreasing along the depth direction. The plastic zone first appears in the soil at the top of anchor rod and expanded head. As the load increases, the plastic zone continues to develop along the axial direction until it penetrates, and the anchor rod fails.

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Last Update: 2025-06-01