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

• Published in: IOP Conference Series: Materials Science and Engineering
• Main Authors: Ji, Yanjun, Hu, Yupu, Jin, Long, Luo, Tao
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2019
• Subjects: permafrost
• Online Access: http://dx.doi.org/10.1088/1757-899x/585/1/012003; https://iopscience.iop.org/article/10.1088/1757-899X/585/1/012003/pdf; https://iopscience.iop.org/article/10.1088/1757-899X/585/1/012003

Abstract 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.