钢螺杆锚桩压重联合静载试验钢梁设计与验证

Design and verification of steel beam for static load test using steel screw anchor pile and weight

为保证大吨位桩基静载试验安全实施,加载反力结构的合理设计至关重要。建立了加载反力平台钢梁的简化计算模型,分析不同受荷工况下钢梁的内力与变形发展规律,并对主、次钢梁截面尺寸进行优化设计。最后,针对实际静载试验项目对钢梁竖向位移、倾斜及锚桩抗拔力进行监测,验证钢梁计算模型的合理性。分析结果表明,钢梁在整个静载试验过程中的变形实测值均小于理论计算值;当施加的静载试验总反力超过堆载块和钢梁自重后,钢螺杆锚桩参与受荷,随着加载荷载的增大,其抗拔承载力的贡献逐渐增大;对于采用钢螺杆锚桩联合压重反力装置的静载试验,监测的各根钢梁竖向位移和倾斜总体一致,未出现明显偏心受力情况,表明该静载试验方法具有较高的安全性。

In order to ensure the safe implementation of large-tonnage pile foundation static load test,the reasonable design of loading counterforce structure is crucial.A simplified calculation model of the steel beam of loading counterforce platform was established to analyze the development of the internal force and deformation of the steel beam under different loading conditions,and the cross-section dimensions of the primary and secondary steel beams were optimized.Finally,the vertical displacement,inclination and anchor pile pullout force of the steel beam were monitored for the actual static load test project to verify the reasonableness of the calculation model of the steel beam.The analysis results show that the measured deformation of the steel beam during the whole static load test is smaller than the theoretical calculated value;after the total reaction force applied in the static load test exceeds the stacking block and the self-weight of the steel beam,the steel screw anchor piles are involved in the loading,and with the increase of loading load,the contribution of their pullout capacity gradually increases.For the static load test using the steel screw anchor pile combined compression weight counterforce device,the monitored vertical displacement and inclination of each steel beam are generally consistent,and there was no obvious eccentric force situation,which indicates that the static load test method has high safety.