Research on Foundation Deformation and Structural Stress Variation of Shaft Tower under the Influence of Frost Heave and Thaw Settlement

Abstract

As the laws of structure deformation and structural stress variation under freezing construction around high-rise buildings are not clear and no engineering experience can be referred to, freezing method construction in this situation is paired with huge safety risks. In this paper, freezing construction was successfully carried out around the main shaft tower in Chensilou Coal Mine by taking the following protective measures: symmetrical drilling, local freezing and hot water circulation. The elevation of the shaft tower foundation is continuously measured during the process of drilling, frost heaving and thaw settlement (hereinafter referred to as the DHS process). Benefiting from these protective measures, the maximum inclination value (−0.406 mm/m) of the shaft tower is controlled at well below the allowable value. The observation data informed the settlement and inclination of the tower foundation during the DHS process. A numerical model of the shaft tower is further established based on the observation data to reveal the tower structure’s law of stress variation during the DHS process. In addition, the fitting equation between the tower inclination value and the structural stress is obtained, which can provide a reference for freezing construction of similar high-rise buildings.

Numerical simulation of frost heave of saturated soil considering thermo‐hydro‐mechanical coupling

“…The frost heave amount decreases when the stiffness of the restraints become higher, and at the same time larger frost heave pressure can be generated. This phenomenon has been also analyzed 4 The effects of stiffness on the frost heave amount and frost heave pressure.…”

“…The uplifting ground induced by frost heave can directly cause many engineering problems, for instance, embankment deformation and building inclination. [1][2][3][4] In addition, when frost heave takes place under confined conditions, it may lead to significant soil pressure, resulting in damage on the overlying infrastructures, such as pipe rupture and foundation failure. 5,6 Both frost heave amount and frost heave pressure are of great concern, and they often occur simultaneously during the soil freezing process, which involve the complicated interaction between thermal, hydraulic and mechanical processes, as well as the phase change of the pore water.…”

“…Frost heave, mainly caused by water migration and growth of ice lens, is a common phenomenon in cold regions. The uplifting ground induced by frost heave can directly cause many engineering problems, for instance, embankment deformation and building inclination 1–4 . In addition, when frost heave takes place under confined conditions, it may lead to significant soil pressure, resulting in damage on the overlying infrastructures, such as pipe rupture and foundation failure 5,6 .…”