堆载致桥梁桩基偏移机理分析与纠偏技术研究

Analysis of deviation mechanism and deviation-rectification technology for pile foundation of bridge due to abutment loading

桥台边坡堆载过高容易导致相邻桥墩偏压超载,造成桥墩下部的桩基倾斜偏移,引起墩顶盖梁偏位,从而导致架梁困难。针对山东某高速桥梁工程桩基偏移,采用理论分析和数值模拟方法揭示了高边坡堆载作用下桩基的偏移机理;针对可能出现的偏移病害,采用开挖检测和低应变检测法检测桩基完整性和稳定性。根据桩基倾斜偏位现状和发展趋势,在全面总结现有纠偏技术的基础上,提出了桩侧钻纠偏孔卸压、桩侧顶推扶正、桩周开挖空间内回填混凝土加固的综合纠偏处理技术,同时进行地基注浆加固。经过1年多不连续监测,纠偏后桩基未再发生偏移,纠偏效果良好,可为对其他类似工程提供了良好借鉴。

Overloading of abutment side slope is easy to lead to overload of adjacent piers, which causes the pile foundation at the lower part of the pier to tilt and offset the cover beam at the top of the pier, leading to the difficulty of girder erection. In view of the pile foundation deviation of a bridge project in Shandong, the theory analysis and numerical simulation methods were used to reveal the pile foundation deviation mechanism under the high slope heaped-up load;aiming at the possible pile foundation migration disease the integrity and stability of the pile foundation were tested by excavation test and low strain test. According to the present situation and development trend of pile foundation inclination and deviation, the comprehensive summary of the existing deviation rectification technology was conducted to put forward a comprehensive rectifying treatment technology of pile side drilling rectifying hole relieving pressure, pile side pushing and righting, backfilling concrete in the space around the pile, and grouting reinforcement of the foundation. After more than one year discontinuous monitoring, the pile foundation has not deviated again, and the effect of rectifying deviation is good, providing a good reference for other similar projects.