钢筋笼对防超灌装置测量电阻值的影响

为了研究钢筋笼对基于测量电阻值的防超灌装置的影响，采用室内试验的方法，通过改变单根钢筋在不同介质中与探头的间距，以及改变钢筋笼上钢筋的数量及位置，探究单根钢筋及钢筋笼对防超灌装置所测得的最终电阻值的影响。研究结果表明：当单根钢筋插入所测介质时，测得的电阻值随着钢筋与探头间距的增大而增大，且逐渐趋近于介质中未插入钢筋时的电阻值。当探头在绝缘杆笼上时，将临近位置绝缘杆替换为钢筋，四种介质所测中所测电阻值均显著减小；继续将其他绝缘杆替换为钢筋时，电阻值几乎无变化。当探头在钢筋笼上时，将除探头所在外的其他钢筋杆顺次替换为绝缘杆，电阻值基本不发生变化。结合单根钢筋及钢筋笼对防超灌装置测量电阻值的试验研究，自主设计一种新型标定器，用以准确测量防超灌系统中的最终电阻值，精确度较高，操作简单，可完全模拟混凝土灌注桩中有钢筋笼时的效果，方便工程应用。

The Effect of Steel Cage on the Resistance of Anti-overfilling Device

The method of indoor test is used to study the influence of rebar cage on anti-overfilling device based on the measured resistance value.The influence of single rebar and rebar cage on the final resistance value measured by the anti-overfilling device is investigated by changing the distance between the single steel bar and the probe in different medium, and changing the number and position of the rebars on the rebar cage.The results show that when a single rebar is inserted into the measured medium, the measured resistance value increases as the distance between the rebar and the probe increases, and gradually approaches the resistance value when the rebar is not inserted in the medium.When the probe is on the insulating rod cage, the adjacent position insulating rod is replaced with the rebar, and the resistance values measured in the four media are significantly reduced.Continue to replace the other insulating rods with rebars and the resistance values are almost unchanged.When the probe is on the rebar cage, the other rebars except the probe are sequentially replaced with the insulating rod, and the resistance value does not change substantially.Through the experimental study on the resistance value of the anti-overfilling device for single rebar and rebar cage, a new type of calibrator was designed to accurately measure the final resistance value in the anti-overfilling system.The device has high precision and simple operation, and can completely simulate the effect of the rebar cage in the concrete pouring pile, which is convenient for engineering application.