通过测斜数据预判测斜管失效的分析方法研究

岩土测斜仪已广泛应用于现场土体和结构物的变形监测，其工作原理是通过测量测斜管的变形以反映监测对象的变形，用于工程的稳定性和安全分析。当工程的稳定和安全受到威胁的时候，往往伴有局部过大的变形现象发生，这可能造成测斜探头不能放入测斜管内，使测斜管失效、关键数据缺失。为预判测斜管失效的可能性，提出5种方法确定测斜管局部变形曲线的曲率或折角，并与测斜管失效时的极限曲率或极限折角进行对比，分析失效的可能性。通过某基坑开挖工程1根测斜管失效的实例分析，对比所提出方法的适用性，从中推荐五型值点单点约束拟合双圆弧法，用于判别测斜管失效。

Study of inclinometer data analysis methods for pre-detecting of failure of an inclinometer casing

Geotechnical inclinometer system is widely used in field monitoring of the deformations of soils and structures.Its working principle is that the deformations of an inclinometer casing are measured to reflect the deformations of monitored objects,with which engineering stability and safety can be analyzed.While the engineering stability and safety is under threat,accompanying oversize localized deformations are of common occurrence.This may result in that inclinometer probe cannot be lowered into inclinometer casing,leading to failure of the casing and losing of key data.In order to predict the possibility of the failure of the casing,5 methods are proposed to determine the curvature or the deflection angle of localized deformation curves of the casing.By comparing the calculated curvatures or the deflection angles with their limiting values at failure,the possibility of casing failure is analyzed.A case of the failure of an inclinometer casing in a foundation excavation project is analyzed.The adaptability of the proposed methods is compared.Of the 5 methods,the method of biarc fitting of 5 data points with an end point constraint is recommended for detecting the failure of an inclinometer casing.