Chemical Water-rock Interaction & Contribution To Landslide Preparation Process

Chemical water-rock interaction (CWRI) widespread exist in nature, which is main factor of process of rock and mineral deformation, whole global environment change, also is the main reason inducing geologic disaster such as collapse, landslide and mud-rock flow etc. Generally analyzed the process of CWRI and the contribution to landslide preparation process according to rock thin-section authentication, scanning electron microscope, rock complete analysis and X-ray diffraction.The process of CWRI means various chemical reactions between water and rock, which occurs in the main kinds of dissolution and accompany hydrolysis, hydration and oxidization-reduction etc., as a result, the microscopic structure changed. The results of above experiments indicate that the mineralogical composition of rock changed remarkable after CWRI: silicate mineral such as feldspar, mica etc. changed into montmorillonite, illitizate or kaolinite, the carbonate mineral such as calcite dissolved and run off; because mineralogical composition changed and be washed away, rock construction unconsolidated, pores and fractures further developed, mineral particle destroyed and become tinier; rock chemical weathering coupled result from chemical, mechanical and physical reaction between water and rock, the level of rock weathering is not uniform, it means CWRI is uncontinuity; inner rock which has no chance to contact with underground water also weathered partly, the mechanism should be the steam which get into rock inside and rotten the rock. The study of the kinetics of silicate and carbonate dissolution show that the mineral dissolution velocity was largely different between in laboratory and in nature because of the difference of mineral particle diameter and experiment condition; the dissolution velocity is concerned with temperature, dissolution time, pH value, organic content etc.The crack of slope rock is growth and link up in various pattern under CWRI and liquid pressure, which cause rock and rock mass developed into loose material and the strength reduced. Clay mineral which formed in the process of chemical water-rock interaction moving and gathering can affect the construction, mechanical quality, deformation behavior and strength of rock and rock mass: rock and rock mass will evolution into loose media under the function of viscosity and like "cubricant" of clay mineral; clay mineral in rock mass structure can reduce c and φ; it can raise the ability that the slope absorb the precipitation. Slope stability mainly based on the maximum force, which can resist slope sliding and interrelated c and φ closely, drop of c and φ is the main reason of slope losing stability.In a word, the contribution of chemical water-rock interaction to landslide preparation process is notable.