超长钻孔灌注桩施工及承载试验研究

Construction and Bearing Test of Super-Long Bored Pile

依托甘肃省某五跨预应力混凝土连续刚构桥开展软基成桩施工关键技术介绍,并且进行试验桩承载特性分析,研究结果表明,试验桩在设计承载荷载(6800 kN)具备5.3 mm左右的桩顶竖向沉降,最大荷载(13700 kN)下的桩顶沉降达到了27 mm,工后沉降稳定在10 mm;试验桩轴力在顶部位置的变化幅度较大,随深度呈凸形;试验桩承载能力满足设计承载要求。

Based on a five-span prestressed concrete continuous rigid frame bridge in Gansu Province,this paper introduces the key technology of soft foundation pile construction,and analyzes the bearing characteristics of the test pile.The research results show that the test pile has a vertical settlement of about 5.3 mm at the design bearing load(6800 kN),the pile top settlement under the maximum load(13700 kN)reaches 27 mm,and the post-construction settlement is stable at 10 mm;The axial force of the test pile changes greatly at the top position,and is convex with the depth;The bearing capacity of the test pile meets the design bearing requirements.