预应力管桩制作过程中钢筋计埋设研究

Study on installation techniques of vibrating wire rebar meter in production process of prestressed pipe pile

振弦式钢筋计已成为检测桩身轴力的有效手段,但设置于预应力管桩时,由于管桩生产工艺易造成钢筋计测量元件,尤其是钢筋计与信号线的接头损坏导致传感器成活率下降.在某预应力管桩成桩过程中,改进钢筋计在钢筋笼上的安装工艺,提高预应力管桩生产过程中钢筋计的成活率.通过改进钢筋计与信号线的连接方式,提高信号线的伸缩变形能力;为避免信号线的损坏,将其沿钢筋笼固定,靠近桩端时收拢引至桩端,并与盖板固定;同时,减少钢筋计连接杆焊接、起吊钢筋笼等过程中对钢筋计损坏,加强关键管桩施工工艺后钢筋计信号的测量.测试结果表明,本次试验共制备管桩10节,每节桩长为15m,共设置100只振弦式钢筋计,全部制作完成后共损坏1只,检测结果表明成活率达99%.

Vibrating wire rebar meter has become an effective means to accurately measure the internal axial force of the pile.However,when it is installed in the prestressed pipe pile,the survival rate is relatively low because the sensor is easy to be damaged in the pipe pile fabrication process,especially at the joint of the vibrating wire rebar gauge and the signal cable.In the process of forming prestressed pipe piles for a certain project,the installation process of the steel bar gauge on the steel cage is improved to increase the survival rate of the steel bar gauge during the production of the prestressed pipe pile.By improving the connection between the rebar meter and the signal line,the expansion and deformation ability of the signal line is improved;in order to avoid damage to the signal line,it is fixed along the reinforcement cage,and when it is close to the pile end,it is drawn to the pile end and fixed to the cover plate.The damage to the rebar gauge should be avoided in the welding of the rebar gauge connecting rod and the lifting of the rebar cage,and the measurement of the rebar gauge signal should be conducted after the key pipe pile construction process.A total of 10 pipe piles were prepared in this experiment,each pile length was 15m,and a total of 100 vibrating wire rebar meters were installed.After all of the pipe piles were made,only 1 rebar meters was damaged.The test results show that the survival rate is 99%.