关键词: 富水砂层, 斜井冻结壁, 热物理及力学特性, 冻融过程, 冻结压力, 温度场

Abstract: Mechanical properties and temperature field of inclined frozen wall provide reliable basis for solving technical difficulties of inclined frozen mine construction in the water-rich sand stratum. Taken the inclined frozen engineering in northern Shaanxi as an example, thermo-physical and mechanical properties of frozen sand were studied by the combination of laboratory tests, field measurement and the finite element simulation. The variation and causes of freezing pressure in inclined frozen sand well were analyzed and the measured temperatures were compared with numerical results obtained in thermometer holes. It is found that the thermal conductivity of frozen sand initially increases and then decreases with the decrease of temperature, and the internal friction angle of frozen sand was greatly influenced by freezing temperature. The freezing pressure was significantly affected by the freezing temperature, shaft depth and groundwater. The effect of the concrete hydration heating on the frozen wall was in the range of 460 and 475 mm. The results provide evidence for the optimization design and stability of inclined mine construction by frozen in the water-rich sand stratum.

Key words: water-rich sand stratum, inclined frozen wall, thermo-physical and mechanical properties, frozen-thaw process, frozen pressure, temperature field