灌浆压力测量误差的正交试验分析

Orthogonal experimental analysis of measuring error for grouting pressure

灌浆规范中的灌浆压力是作用在灌浆岩体上的孔内灌浆压力。由于工艺的约束,现行灌浆监控过程常用孔口压力表示孔内灌浆压力,造成了灌浆压力的测量误差。针对非循环灌浆工艺,通过建立流体管道流动模型开展数值计算,采用多因素多水平正交法探究灌浆压力误差受浆液配比、浆液流速、灌浆孔深的相对影响,并采用统计法来分析不同工况下的显著影响因素。研究结果表明:灌浆压力较小时,灌浆压力误差普遍较大;若此时灌浆孔深且流速较大时,灌浆压力的测量误差则会超过灌浆压力仪表0.5%的精度要求,须进行误差补偿。其次,极差分析结果表明灌浆孔深是造成测量误差的主要因素,灌浆流速是第二个主要因素。而综合所有试验结果,浆液流速和灌浆孔深接近时,浆液配比越小,绝对偏差越大。结合上述正交试验和数值模型获取了不同工况下孔内灌浆压力值。

Grouting pressure is down-hole pressure on the crack of grouting hole.Due to the constraints of grouting art,the grouting pressure is presented by the pressure of up-section of pipe,which produces measurement error of grouting pressure.the fluid flow model of grouting pipe for numerical computing is constructed,and orthogonal experimental method to analysis the error of grouting pressure influenced by cement grout ratio,grout velocity and grouting depth is adopted.And the significant factor is presented based on statistical method in different grouting conditions.The results demonstrate that grouting pressure is lower,the error of grouting pressure is bigger,and the relative error would exceed the up-bound precision of pressure sensor with 0.5%,and the measuring value must be revised.Secondly,the analysis of rangeresults demonstrate conditions.The research results demonstrate that grouting pressure is lower,the error of grouting pressure is bigger,and the relative error would exceed the up-bound precision of pressure sensor with 0.5%,and the measuring value must be revised.Secondly,the analysis of range results demonstrate the grouting depth is the main factor of error,And the flow velocity of grouts is in sequence.The absolute error is bigger with smaller grouts ratio on the same grouting depth and flow velocity.Combining orthogonal test method and numerical computing,a computing method of grouting pressure in the grouting hole is presented.