膨胀式自应力灌浆卡箍压力测定方法

The method of pressure measurement for expansive stressed grouted clamp

膨胀式自应力灌浆卡箍中膨胀水泥环施加于受损内管表面的压力对该类型卡箍的滑动承载力有决定性的作用,因此测量卡箍中膨胀水泥环产生的压力对研究该类型卡箍的性能十分重要。介绍卡箍试件养护期间直接测量水泥膨胀导致的受损内管变形应变的方法以及膨胀压力的计算方法,该方法能够很好的祛除温度及垂直于应变花表面法向压力对测量结果的影响,准确地测定水泥膨胀过程中内管不同位置的应变变化。同时介绍通过测量卡箍螺栓的伸长间接测量膨胀水泥环对损伤内管表面平均压力的方法。试验表明在水泥浆中掺入FEA膨胀剂能够在灌浆环与受损内管表面间快速产生较大的径向压力,提高卡箍的滑动承载力。

The radial pressure normal to the damaged inner tube surface induced by expansive grout annulus plays a crucial role in the slip capacity of expansive stsessed grouted clamp.So it is very important to measure the pressure induced by the expansive grout annulus for researching the performance of such type of clamps.This paper introduces the method for directly measuring the strain of damaged inner tube induced by expansive grout annulus during the period of clamp maintenance and the calculation method for expansive pressure.The method for strain measurement can eliminate the influence of temperature variation and the pressure normal to the strain rosette surface on the measurement result and precisely measure the strain variation on different positions of inner tube during the expansion process of grout.The method for indirectly measuring the average pressure normal to the damaged inner tubular surface is also introduced by measuring the length variation of the clamp bolts.The test indicates that mixing of FEA expansive agent in cement slurry can quickly produce relatively large radial pressure and improve the slip capacity of the clamp.