Research on the Sensitive Chemical Weathering Indices to Rock Weathering

Weathering is an important factor leading to the deterioration of mechanical properties of rocks,and the sensitive indices of weathering are the basis for quantificationally evaluating weathering degrees of rocks and determinging the depth of rock weathering.In this paper,based on a large number of chemical test data of rock samples under different weathering grades,time and different depths,the sensitive chemical weathering indices are studied.The study indicates that among the chemical weathering indices previously proposed,WI,WPI and LOI,show apparent monotonicity and sensitivity corresponding to the variations of weathering degree,time and depth.Therefore,the three indices can be used to evaluate the weathering degree of rock,and to determine the depth of weathering.Otherwise,ALK,a and b show no monotonicity corresponding to the variation of weathering degree,so they can not be used to evaluate the weathering degree of rock and determine the depth of weathering,either.