Research On The Calculative Width Of A Laterally Loaded Pile In Xigeda-Rock

Xigeda-rock is distributed in the southwest region of China. It belongs to extreme soft-rock with some special characteristics, such as being sliming and softened by water, dehydrated cracking and so on. The research data about this rock and cast-in-place pile in it is very scarce. The clear computational methods of the calculative width of the pile in current criterions have not yet been found. So it has theoretical and practical meaning to discuss the calculative width of the pile in Xigeda-rock.Mainly based on the sub-subject "Testing Study on Bearing Behavior of Pile Foundation in Xigeda-Rock" of the western traffic scientific research project "Research on Highway Construction Techniques in Xigeda-Rock" , and associated with the provincial scientific research project "Testing Study on Bearing Capacity of Bored Pile in Xigeda-Mudstone of Xichang-Panzhihua Expressway", this paper does some comparatively systematic research on the appropriate calculative width of single laterally loaded pile in Xigeda-rock. Firstly, according to the summarize and analysis of the laterally static load test data of single pile on Xinjiu site, the bearing behavior and ultimate bearing capacity of the tested pile are got. Secondly, according to the measured data, different width is applied to calculate the test pile's bearing capacity by the m method. The author gains the curves of stress and displacement of pile on basis of the above results, and sums up the regularity of the effect of calculative width on the above curves .Thirdly, the author researches the influencing factors on the calculative width of single pile in Xigeda rocks by ANSYS software, i.e. the pile diameter, pile length, pile shape.The results show that in Xigeda rocks, for the circular (square) pile, the pile diameter (width) is less than 1m, the stress condition coefficient K₀ increases as the pile diameter(width) decreasing; yet pile diameter (width) is greater than 1m, K₀ increases as the pile diameter(width) increasing and achieves minimum when the pile diameter (width) is 1m. In addition, The analysis also shows that the value for form factor K_f of circular pile is still 0.9, the pile length has little effect on its calculative width. Meanwhile, a new method to calculate the calculative width for a single pile in Xigeda rock is proposed.