Pile End Grouting Pile Bearing Capacity Of The Pilot Study

The drilling hole pour pile's bearing capacity is slackened grievously because of sediment at bottom pile. Starch-pressing technology after pouring pile can effectively remove the sediment at bottom pile and improve the bearing capacity of the bottom of pile. And it can also improve friction of side of pile by strengthening side soil because of the permeation of serosity around of the pile.This paper sums up the strengthen theory and the factor of effect about poured serosity as well as investigates the calculation about bearing capacity about drilling hole pour pile after pouring. On the basis of in-site test of piles, this paper investigates the technology of pressure pouring under pile's bottom about the drilling hole pour pile whose bottom is in the badness class gravel soil. The test indicates that the pressure grouting pile's bearing capacity is more ameliorative than the common pile. But many factors, including drilling, concrete poured and pouring serosity can cause the uncertainty of the pressure grouting pile; Pressure grouting can obtain early displays the exertion of the resistance at the pour pile bottom and can improve the ultimate friction resistance, the ultimate friction resistance of ordinary pile is between 15～39kPa, but the minimization ultimate friction resistance of pouring pile is 37kPa, the maximization ultimate friction resistance of pouring pile over 74kPa; The relative displacement of pile-soil of ordinary pile is 4.5mm when the friction resistance achieves the utmost, The relative displacement of pile-soil of pouring pile is more than 7mm when the friction resistance achieves the utmost, so this conclusion can be drawn that the starch-pressing technology after pouring pile can strengthen the soil around of the pile.On the basis of static loading experiment, the bearing capacity of pressure grouting pile is simulated by means of MARC program. And according to the simulated of pouring at bottom of pile, at the side of pile, and both of them. The simulation indicates that all of them can improve the bearing capacity of the drilling hole pile, and with the same serosity pressure grouting at the bottom pile improved bearing capacity is better than the others.