An attempt is made to interpret the strain measured along a strain-pipe embedded in landslide areas with the aid of a continuous curve fitting by cubic spline functions. The aim of the present research is to identify the slip planes in the particular areas as well as to evaluate the current extent of the sliding movement. The strain-pipe employed is made of a plastic material with strain gauges attached on its side wall. The pipe is penetrated into stable layers beneath a slope so that the

more »

... m tip is fixed. The pipe is modeled as a beam lying on an elastic foundation. The theory of beams suggests that the strain measured by gauges are proportional to the bending moment whose first-order derivative is equal to the shear force. The maximum shear force is expected to occur at an elevation close to the slip plane. Furthermore, the lateral displacement of the pipe and surrounding soils can be evaluated by integrating the moment twice along the pipe. The method described above was used for two case studies at the Er-Jen Mountain and the Lung-Tan District. By comparing the results with those of the limit equilibrium analyses, it was found that both strain-pipe and numerical methods gave very similar locations of slip planes.