The Study On Engineering Measures For Reducing Unfavorable Soil Squeezing Effect Due To Pile-sinking

The economy brings along fast development in civil engineering ,the use of pile foundation becomes very common, and the prestressed-concrete pipe pile has been used frequently in recent years. One of the most useful pile-sinking method for prestressed-concrete pipe pile is static pressure method, the static pressure pile has some merits, such as the quality of pile body is easy to check and ensure, the price is relatively low, high work efficiency and no slop pollution. The prestressed-concrete pipe pile belongs to the pile which will squeeze and substitute soil. The phenomena of soil squeezing in pile-sinking will do harm to the latter construction and the environment. The soil squeezing effect of the prestreesed-concrete pipe pile in pile-sinking is very distinctness. The large extrusion effect in pile-sinking drives the soil in pile area heaves and moves horizontally, and the pile body lift, deviate, break off.This paper begins with the theories of cavity expansion method (CEM), analyze the mechanism of soil squeezing, give two engineering cases, and summarize some popular engineering measures for reducing unfavorable soil squeezing effects.This paper lists five engineering cases which has already been constructed, conclude the engineering measures for reducing unfavorable soil squeezing effects in design and construction. In the way of design: reasonable design, pre-drill pile-sinking, dig avoiding squeezing soil groovy, set stress release bore, plant plastic drain plate; In the way of construction: reasonable piling order, control of pile-sinking velocity, estimate soil squeezing displacement in advance. Meanwhile, it's presented in the paper that measures such as digging the groovy and pre-bording are analyzed and evaluated.At deepth of 8m under the ground, soil squeezing displacement is of great difference with or without pre-bording, and the difference becomes slight when the depth increases.There is obvious influence to squeezing when the groovy which is used for avoiding squeezing soil is made. The soil displacement in front of the groovy appears to largen, while behind it is far smaller then without groovy.A case of pile-sinking is bring forward in every forementioned engineering measure, then embody analysis and evaluation of applying the measures are made in the paper.