Variation of Ground Temperature along the Stratum Depth in Ice-rich Tundra of Hinggan Mountains Region, NE China

Abstract

A pile foundation in a permafrost region is in a negative-temperature environment, so concrete is affected by the negative temperature of the surrounding soil. It not only affects the formation of concrete strength but also leads to engineering quality accidents in serious cases. With the support of the two permafrost bridge projects of the national highway from Beijing to Mohe in the Greater Khingan Mountains region, a systematic remote dynamic monitoring method for ground temperature in ice-rich tundra is proposed. Based on the actual measurement of temperature at different strata depths and the comprehensive consideration of surface temperature, terrestrial heat flux and other parameters, the ground temperature profile evolution in relation to depth in Greater Khingan was established. The theoretical ground temperature profile curve is similar to the measured profile. The results show that the variation trends of ground temperatures in relation to the strata depth at different monitoring sites is similar, and all show seasonal variation: From June to November, the ground temperature at different depths tends to be constant. From December to May, the ground temperature at any depth within the range of 0 to 5.5 m follows the curve of the cosine function. Below 5.5 m, the earth temperature no longer varies with depth. The research results can be used as reference for pile foundation construction in a negative-temperature environment in ice-rich tundra.

Keywords

• permafrost
• temperature
• nonlinear fitting
• prediction model