Determination of rock mass deformation modulus by means of Traveling Load Tests—Part II: Traveling Load Test practice in an open pit

Determination of rock mass deformation modulus by means of Traveling Load Tests—Part II: Traveling Load Test practice in an open pit

K. Sugawara^*, L. Faramarzi, N. Nakamura

Graduate School of Science and Technology, Kumamoto University, Japan

Doi: 10.1016/j.ijrmms.2005.06.002

Abstract

A case study makes clear the applicability and high potential of the Traveling Load Test in an open pit. The induced tilt-loading distance curve is measured by means of a series of stationary loading tests over a short time, so as to avoid semidiurnal variation of initial tilt by the earth tide. Through a series of data processing, the deformation modulus of rock mass is determined as a function of Poisson’s ratio by the values of the peak tilt and peak distance on the induced tilt-loading distance curve and the magnitude of load subjected, regardless of the depth of tilt measurement and the thickness of surface damages. The test results represent the macroscopic deformation modulus of rock mass, covering an area much wider than the conventional load tests. Additionally, analyzing the signal to noise ratio of the traveling load test in an open pit, it is discussed that the lack of load is a problem to be settled by future studies.

Keywords: Deformation modulus; In-situ loading test; Tilt measurement; Earth tide