高填方地基内部沉降监测装置的研制

Development of an Apparatus for Measuring Subsurface Settlement of Deep Filled Ground

传统监测装置用于大面积高填方地基内部沉降监测时,存在测量元件埋设难度大、施工期观测困难、不易实现自动化监测等缺点.为此,研发了一种高填方地基内部沉降监测新装置.该新装置主要由电感调频式位移计、位移传递杆、沉降板、锚固头、保护套管和沉降观测标等部件组成,其中电感调频式位移计与位移传递杆串联连接,用于观测相邻监测点之间的压缩沉降,接入自动化采集系统后可实现自动化监测.该新装置采取原地基中钻孔埋设与填筑体中探井埋设相结合的埋设方法,随土方施工分段埋设至高填方内,通过分层测量、逐层累加的方法获得各监测点的沉降.现场应用试验结果表明,新装置的结构设计合理,配套埋设工艺可靠,监测数据准确完整.新装置适用于采用均质土料分层压实的大面积高填方地基内部沉降监测.

The conventional measurement apparatuses are unsuitable to measure the subsurface settlement of the deep filled ground over a large area due to the technical difficulties associated with installation,measuring during construction,and automatic measurement. In this study,a new apparatus is developed to measure the subsurface settlement within a deep filled ground.The major components of the new apparatus include an inductance frequency-modulated displacement meter,a displacement transfer rod,a settlement plate,an anchorage head,a protective sleeve,and a settlement observation rob. In particular,the inductive frequencymodulated displacement meter is connected in series with the displacement transfer rod,which is used to measure the compression settlement of two adjacent monitoring points. The inductive frequency-modulated displacement meter of the new apparatus can be connected to an automatic data acquisition system such that the subsurface settlement can be measured automatically. The new apparatus is first installed into a borehole within original ground and then an exploratory well within filled ground gradually as the construction of earthworks proceeds. The subsurface settlement at different depths can then be obtained by summing the incremental settlements measured between adjacent monitoring points. A field experiment via application of the new apparatus to a deep filled ground indicates that the design of the new apparatus is reasonable,the installation method is reliable,and that accurate and continuous measurements of the subsurface settlement can be obtained from the new apparatus. The new apparatus is suitable for measuring subsurface settlement of the deep filled ground which is made up of compacted homogeneous fill soils in layers over a large area.