(1. College of Water Conservancy and Hydropower Engineering，Hohai University，Nanjing，Jiangsu 210098，China；2. Boyan Water Resources and Hydropower in Xinjiang Environmental Technology Co.，Ltd.，Urumchi，Sinkiang 830000，China)
Abstract：Permeability of fracture is sensitive to the dissolution of minerals under the medium temperatures(25 ℃–90 ℃) and osmotic pressures. The flow-through experiments were therefore conducted on the limestone containing a single fracture under 4 different temperatures，25 ℃，50 ℃，70 ℃ and 90 ℃ respectively. The seepage discharge and hydraulic equivalent width of aperture affected by the temperature variation was studied to investigated the permeability characteristics of limestone fracture. During the reaction process，the seepage discharge and the ionic concentration of percolate were measured. The seepage discharge was transformed through the cubic law to obtain the variation of fracture width with time. The experimental results show that the seepage discharge and the hydraulic equivalent width of aperture in the process of temperature rising increase significantly with the time. The hydraulic equivalent width of aperture in the process of constant temperature decreases gradually and finally reaches a stable value. After the increase of osmotic pressure，the width of aperture under the constant effective stress decreases as the increase of temperature. It was found that raising temperature promoted the effect of stress and seepage，and the partial dissolution of seepage channel also changed with the variation of temperature，thus influenced the process of pressure dissolution and free dissolution.
2017, Vol. 36 
