Experimental Study on Key Design Parameters of Cast-in-situ Pile Foundation in Permafrost Regions

5th Annual International Workshop on Materials Science and Engineering

Ji, Yanjun^1 ; Hu, Yupu^1 ; Jin, Long^2 ; Luo, Tao^1

Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi'an

710123, China^1

CCCC First Highway Consultants Co., Ltd., Xi'an

710075, China^2

关键词: Cast in place pile;    Cast-in-situ pile;    Key design parameters;    Permafrost region;    Pouring temperatures;    Thermal physical parameters;    Transient method;    Water binder ratio;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/585/1/012003/pdf
DOI  :  10.1088/1757-899X/585/1/012003

来源: IOP

【 摘 要 】

The freezing strength of pile foundation in contact with permafrost is the key parameter for calculating the bearing capacity and pull-out stability of foundation. The thermal physical parameters of concrete before initial setting under various conditions were measured by a thermal conductivity meter based on the transient method. The effects of water binder ratio and pouring temperature on the thermal physical parameters were analyzed. The results show that the ratio of water to binder increases from 0.4 to 0.6, the thermal conductivity and thermal diffusivity decrease and the specific heat increases correspondingly; the thermal conductivity is negatively correlated with the pouring temperature, while the specific heat and thermal diffusivity are not significantly correlated with the pouring temperature. Based on the above research results, it is suggested that the water binder ratio of 0.4-0.45 and the pouring temperature of 5-10°C should be adopted in the design of cast-in-place piles in permafrost regions.