城市高架桥群桩基础沉降量计算评价

探讨城市高架桥群桩基础沉降量计算评价方法,为桩基沉降安全评价提供理论依据。在详细总结深厚软土层区群桩基础沉降的影响因素和目前工程中常用的沉降量计算方法的基础上,针对具体的工程实例采用等代墩基法、等效作用分层总和法、弹性理论法以及Flac 3D数值模拟方法分别计算了高架桥群桩基础的沉降量和应力位移场变化规律,并与实测数据进行对比分析。结果表明,采用弹性理论法和等代墩基法计算沉降量与实际吻合较好,等效作用分层总和法和数值模拟方法计算结果虽然偏大,但应用的范围较广。至少3种方法得到的沉降量均小于允许值,才能判定沉降量满足安全要求。

Research on settlement calculation and evaluation of pile foundation of urban viaduct

This article discusses the calculation and evaluation method of the settlement of pile group foundation of urban viaduct,and provides theoretical basis for the safety evaluation of pile foundation settlement.Based on the influence factors of pile foundation settlement of deep soft soil stratum,current computing methods in engineering of settlement,such as equivalent footing method,equivalent sum of slice,elastic theory method and Flac 3D numerical simulation method,are separately used to calculate the settlement and to analyze the change regularity of stress and displacement fields to viaduct in specific engineering project and compared these research results with the measured data.The results show that it is better to use equivalent footing method and elastic theory method in the practice application.Though,equivalent sum of slice and numerical simulation method have a popular application,they usually yield larger results which affect the engineer project.This research provides a reliable foundation for the settlement evaluation of pile foundation of similar engineering geological conditions.It reveals that only the settlement value is calculated by at least three or more methods and the calculated settlement value less than allowable value,can it meet the safety requirements of construction.