混凝土预制装配式扩展基础抗拔试验  

PULLOUT BEHAVIOR OF PRECAST CONCRETE ASSEMBLY SPREAD FOUNDATION

作　　者：鲁先龙[1,2] 乾增珍[1] 童瑞铭[2] 

机构地区：[1]中国地质大学(北京)工程技术学院,北京100083 [2]中国电力科学研究院输变电工程力学研究所,北京100192

出　　处：《工程力学》2013年第1期215-220,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(51208480)

摘　　要：根据预制装配式基础在上拔荷载作用下的室内足尺试验,监测了试验加载过程中基础构件的位移和应力变化,研究了预制装配式基础在上拔荷载作用下的协同工作性能。试验结果表明:在上拔荷载作用下:1)预制装配式基础连接法兰盘、底板拼装连接缝附近测点的上拔位移变化规律与基础顶部基本一致,基础各构件之间整体承载性能好。基础荷载-位移曲线分弹性、弹塑性屈服和破坏3个阶段;2)法兰盘连接锚栓、槽钢连接锚栓和连接槽钢等各构件的测点应力均随荷载增加而增加,且处于弹性阶段;3)预制装配式基础拼装底板以拼装缝为轴,呈两边向下弯折趋势,基础底板外边缘角点上拔位移量小于基础顶部,且相同部位连接构件在同一级荷载作用下的应力状态和应力大小呈不同的变化规律;4)基础拼装间隙、拼装过程中螺帽拧紧程度以及基础预制加工误差是预制装配式基础共同工作性能的影响因素,但其整体工作性能好,可按土重法计算基础抗拔极限承载力。The precast concrete assembly spread foundation for Qinghai-Tibet AC750kV/DC±400kV grid interconnection project in a frozen soil area was tested under pullout loading. The mechanical co-working properties for the different structural parts of the foundation were analyzed based on the monitoring results of their displacement and stress. Under an uplift load, the displacement of the ring flange connecting the column and the bottom slab and the joint seam of the two consolidated bottom slabs conformed with that of the top plane of the foundation. Three stages of the elastic, elastic-plasticity and failure were observed according to loading-displacement curves of the foundation. Moreover, the stress of the connecting anchor bolts and channel beams increased with the tension load. Under a designing load, all connecting anchor bolts and channel beams were in elastic stress status. Because of the structural characteristic of the assembly foundation, the gaps among the assembly parts, the discrepancy of the nut screwing up and the mismatching tolerance existed during consolidating. Therefore, under the tension load and the dead weight of the soil above the foundation, the two edges which were parallel to the joint seam of two consolidated foundation slabs had a tendency to down warping. And the displacements of all angular measuring points were less than the displacement of the top plane of the foundation. The displacement and the stress of the different connected parts redistributed until the new balance developed. As a result, the different connected parts of the precast concrete assembly foundation co-operated to carry the tension load. All structural parts foundation had good entirety. And the earth cone method can be adopted to determine its ultimate uplift beating capacity.

关 键 词：预制装配基础 抗拔 土重法 连接件 协同工作 

分 类 号：TU318[建筑科学—结构工程] TU470