关键词: 公路桥梁, 不对称直桩, m法, 群桩平衡方程, 补桩原则

Abstract: The use of supplement piles is a common remedial measure in bridge construction. The resulting asymmetric pile foundation is calculated according to current highway specifications, which is not closed and unstable. A calculation method for asymmetric straight piles is proposed based on the m-method. Firstly, calculate the stiffness of a single pile and summarize the pile group stiffness at the base of the pile cap. Then establish a balance equation related to the longitudinal and transverse directions. The load at the base of the pile cap is recombined according to the asymmetric structure, and the displacement of the pile cap is determined by solving the equilibrium equation. Next, calculate the external force at the top of each pile in sequence. Then, carry out subsequent calculations according to the current specifications, and finally achieve the calculation of asymmetric pile foundation. It has been verified that this method is accurate, efficient, and easy to operate, making it suitable for inclusion in specifications. Practical engineering applications have demonstrated that the approach of using supplement piles around the bearing platform is structurally sound and straightforward to implement. In case of damage to a side pile, two symmetrically placed piles should be added adjacent to the affected side of the pile cap; for a corner pile damage, one pile should be added at each end of the pile cap; if the middle pile is damaged, one pile should be added to the closest side of the pile cap. To save costs, one pile can be damaged and replaced within a range of 1-2 times the diameter of the abandoned pile. However, as it does not meet the minimum pile spacing requirement, it should be used with caution.

Key words: highway bridge, asymmetric straight pile, m-method, pile group equilibrium equation, principle of supplement pile