测斜仪在路基水平位移监测中的若干问题探讨

结合工程实测数据,对利用土体测斜仪考察路基水平位移过程中的几个常见问题进行了系统性考察.对比分析表明:铝合金测斜管导向槽的扭转较小,而塑料测斜管的扭转问题较为严重;测斜管达到极限变形后,极限弯曲部位以下地方的水平位移无法进一步测量;测斜管两端被相对固定,且测斜管管材的刚度远远大于饱和软土,导致软土与测斜管不能协调变形.可见,基于测斜仪得到的水平位移数值是近似的,有可能因非确定性因素导致监测结果存在较大的误差.因此,需要改进现有的测斜仪测试技术,突破依靠导轮式测头在测斜管导向槽内的滑动来考察水平位移大小的设计理念,减少水平位移测试技术中的误差根源.图6,表1,参8.

Study on Some Issues of Soil Inclinometer in Monitoring Lateral Displacement of Soft Soil Foundation under Embankment

Based on the monitoring value of lateral displacements of some real engineerings, some common issues in the technique of lateral displacement measured by inclinometer were studied systematically. It shows that the twisting angle of aluminium alloy pipe is little, while the twisting problem of plastic pipe is serious. When the deformation of inclinometer pipe arrived critical state, the lateral displacement under the site of critical deformation can not be get conveniently any more. Moreover, the inclinometer pipe can not get compatibility of deformation with soil, for which fixed with both ends by hard soil and have a geater stiffness than soil. So, the value of lateral dispalcement getting from inclinometer is inaccurate in a certain degree, which sometimes has a great error because there are many uncertain factors. Therefore, the technique of lateral displacement measured with inclinometer should be improved, such as the design methodology of gauge head with wheel gliding in the inclinometer pipe can be changed, and the springhead of uncertain factors influence on the testing results should be romoved.