研究目的:为解决目前超长大直径钻孔灌注桩钢筋笼在制作、吊装、安放过程中的变形及安放精度等问题,本文利用桥梁专业有限元软件Midas/civil对超长大直径钻孔灌注桩钢筋笼进行建模分析,模拟钢筋笼在制作过程中各个工序的受力状态以及变形情况,对钢筋笼的制作与安放质量进行控制.研究结论:(1)钢筋笼采用φ28的HRB335级钢筋作为主筋,I12.6为箍筋,吊运时吊点离端部4 m,下放采用16根φ32 mm的主筋为吊筋,分4组吊装在工字钢的两两交汇点,能较好地控制制作与吊装过程的应力与应变;(2)钢筋笼加工采用长线法,每4 m沿圆周均匀布置4个保护层钢筋,上下组保护层水平方向错开200 cm,可以保证桩身混凝土保护层厚度,吊装时利用170 t龙门吊和50 t履带吊同时起吊;(3)保持钢筋笼主筋对接加工与安装的统一性和从材料及施工过程控制声测管的质量,可以有效地避免安全事故,可为以后在滨海地带进行超长大直径钻孔灌注桩的施工提供一定的参考.%Research purposes:In order to solve the problem of deformation and placing precision in making,lifting and fixing of super large-long diameter bored piles' steel reinforcement,the reinforcement cage of super long-large diameter bored piles is analyzed systematically with Midas/civil in order to simulate the stress and deformation states of each process when in the manufacture and installation.Research conclusions:(1) For propose of control the stress and strain of manufacture and installation,b28 grade HRB335 rebar is used to be main reinforcement and I12.6 as stirrup.When lifting,the lifting point is 4 meters from the end,dividing the φ32 main reinforcement into four groups as steel hanger and placing it on the joist steel.(2) To make sure the thickness of pile body concrete protective layer,the long-term construction is used to process the reinforcement cage,every 4 meters along the circumference layout four steel bar as protective layer,and there is 200 cm horizontal direction stagger between up and down.(3) Keeping unification of process and installation of butt joint as well as controlling the quality of sounding pipe in the way of materials and construction process can prevent the accident availably.
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