Volume 18, No. 1, 2024
Received: 2023/07/26, Accepted: 2023/12/14
Authors:
Lijun Wang; Yongxing Dai; Gongning Liu;
Abstract:
To investigate the force evolution law about the micro-steel pipe piles in the excavation process of the metro with the PBA method, based on a metro station project in the Guangzhou area, the mechanical evolution law of single-row and double-row side piles were compared and analyzed based on laboratory model tests. It is found that the soil arch effect appears significantly in the excavation of single-row piles as well as double-row piles, and the distribution of the soil arching effect and the peak stress range is roughly the same, and the soil arching effect shifts downward with the excavation of soil. The stress concentration phenomenon of double-row piles is weaker than that of single-row, and the attenuation range of its stress is much smaller. The soil arching effect between piles formed by the back piles about the double-row pile shows certain shielding effects on the force of the front-pile, which can significantly weaken the soil pressure directly borne by the front piles. Then significantly affect the force of the front piles, and even the tip of the front piles will reverse bend. The research results of this paper can provide an important reference for similar projects.
Keywords:
model test; PBA method; micro-steel pipe piles; earth pressure; mechanical difference