为了推进膨胀式自应力灌浆卡箍技术的工程应用,本文进行了大尺寸卡箍模型的承载性能测试分析,主要通过内管表面多点的应变测试来分析灌浆环内表面的膨胀压力分布,通过测试螺栓拉力来分析灌浆环外表面的平均膨胀压力,最后利用"推出法"测定卡箍的滑动承载力,并结合膨胀压力分布情况进行分析。试验结果表明:灌浆环内表面膨胀压力在各个断面的分布是一样的,但断面不同位置膨胀压力的分布不均匀。由于灌浆环顶部存在空隙,造成了底部膨胀压力最大,两侧的压力较小,顶部是负压力。由螺栓拉力测试的灌浆环外表面平均膨胀压力理论推导出的内表面膨胀压力可以看出,内表面底部测试的膨胀压力比较符合推导值,侧部膨胀压力则偏小。滑动承载力测试时内管表面应变的数值大小也证实了膨胀压力的不均匀分布情况。另外该类型卡箍可以在灌浆后短时间(3~4d)内形成承载能力。

Expansive stressed grouted clamp as an effective maintenance technology improves the installation efficiency of the traditional self-stressed grouted clamp.In order to promote the engineering application of expansive stressed grouted clamp,the capacity performance of a large scale clamp model has been tested and analyzed.The distribution of expansive pressure at the different section of grout annulus is tested as well as the slip capacity.Mainly the distribution of expansive pressure at the inner surface of grout annulus is analyzed by multipoint strain measurement on the surface of inner tube.At the same time the average expansive pressure at grout outside surface is analyzed through the bolt tensile force measurement.Finally the push-out method is adopted to test the slip capacity of clamp,combined the analyses by the distribution of expansive pressure as well.And the expansive pressures are verified by the theoretical values.Experimental results show that the distribution of expansive pressure at the inner surface of grout annulus in each section of the tube is the same,but uneven at different position of the same section.Because there is a gap existing at the top of the grout annulus,the expansive pressure is the largest at the bottom,smaller at side position and even negative pressure at the top position.From the average expansive pressure on the inner surface of grout annulus,which is deduced theoretically from the outside surface average expansive pressure tested by bolt tensile force,we could find out that the bottom expansive pressure on the inner surface from measurement is close to the average expansive pressure value deduced,however the side expansive pressure is smaller than the average.Furthermore through slip capacity test the stain changes on the tube surface are also found to confirm the conclusion of uneven distribution of expansive pressure.At last,this type of clamp could form the slip capacity at very short time(about 3to 4days).The distribution of expansive pressure of large scale clamp model is tested as well as its process of establishing,which can provide valuable test data for the clamp installation application.The design ideas and methods summarized in this paper for expansive stressed grouted clamp can provide effective technical reference for the engineering application in the future.