Study on Uplift Bearing Characteristics of Micropiles in Weathered Rock With Shallow Overburden

DOI

10.2991/978-94-6463-726-7_18How to use a DOI?

Keywords

weathered rock with shallow overburden; micropile; filed experiment; ultimate uplift bearing capacity; pile shaft friction; uplift coefficient

Abstract

In order to investigate the uplift bearing characteristics of micropiles in typical weathered rock with shallow overburden in mountainous areas of Zhejiang Province, China, the vertical uplift static load tests of micropiles were conducted in Ningbo, Taizhou, and Lishui by the Infrastructure Department of State Grid Zhejiang Corporation, respectively. This paper presented the Q-s curves, the axial force distribution of pile shafts, and the exertion of pile side friction of the micropiles obtained from these tests. Comparative analysis was made with the value of ultimate uplift bearing capacity calculated using the standard, and the modified calculated parameter was proposed. The results indicated that the Q-s curves of micropiles in weathered rock with shallow overburden appeared “steeply varying type”, and the exertion of pile side friction was a dynamic process, which was related to factors such as geological properties, load grading, and tensile strength of pile materials. The main reason for the values of ultimate uplift bearing capacity calculated based on the standard being smaller than that measured was the smaller value of the uplift coefficient, and it was recommended that the value of the uplift coefficient in weathered rock with shallow overburden can be in the range of 0.85-0.94. The research findings provide a reference for the design and application of micropile foundations for transmission lines.

Copyright

© 2025 The Author(s)

Open Access

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TY  - CONF
AU  - Bing Feng
AU  - Weiming Ma
AU  - Yong Cai
AU  - Panfeng Li
AU  - Qi Zhang
AU  - Qing Lü
PY  - 2025
DA  - 2025/06/13
TI  - Study on Uplift Bearing Characteristics of Micropiles in Weathered Rock With Shallow Overburden
BT  - Proceedings of the 2024 6th International Conference on Hydraulic, Civil and Construction Engineering (HCCE 2024)
PB  - Atlantis Press
SP  - 174
EP  - 188
SN  - 2589-4943
UR  - https://doi.org/10.2991/978-94-6463-726-7_18
DO  - 10.2991/978-94-6463-726-7_18
ID  - Feng2025
ER  -