The Research Of Precast Pile Bearing Capacity In Fly Ash Venue

Foundation of pile which has a longer history and has been widely used is one type of deep foundations. Research of load-transfer law or bearing capacity and other issues of pile have a very important theoretical and practical significance, which is to the design of pile foundation or construction and others. It is rare to build high-rise in fly ash venue, and lack full understanding about the nature of fly ash, which bring a series of harmful influences in the foundation design of PHC piles, and then it increase much more difficulties in the management,construction and other aspects.Theoretical analysis, laboratory testing, static load test and field trial are used combining with each other in this paper, which is to research and analyse characteristics of settlement and bearing capacity of PHC pile in fly ash venue, the following work were made mainly in this paper:1. Filed data are measured by static load test, also Pile side resistance of foundation is monitored, and the results of monitoring are used to determine the bearing capacity of pile.2. Static load test and stress-strain trial are combined with each other, which are used to research and analysis the Pile side resistance, tip resistance, load-sharing ratio and so on.3. Combined with the practice of engineering, force characteristics of PHC pile are researched and analyzed in the changes of Pile side resistance, tip resistance, axial force and others by static load test and stress-strain trail, and then standard value of ultimate side resistance of fly ash soil is tested.Through research of the static load test, stress-strain trail and others test methods; the main results are as follows in research:1. Capacity eigenvalue of the pile is 2250kN in this paper, the Pile bearing capacity eigenvalue of the value is 2896kN by static load test of pile, and the design of pile foundation is tested further, which is reliable and rational.2. The change in axis force of precast pile is not only in line with the pile basic law of axis force, but also which is consistent with the existing research and theory in fly ash venue.3. The side of the resistance acted on the pile by soil is not a fixed value but a change value, which reduces significantly with sink of pile continuatively.4. As the load of pile increasing, pile side resistance and tip resistance both have gradually increased, but there are obvious differences in their growth, also the proportion of load-sharing is not the same.5. Tip resistance of the pile doesn't play fully in the fly venue, which just plays a very small part, and there are still large reserves of the tip resistance.Through the results in this paper, which illustrates that the study of PHC pile is very important in the fly ash venue further, also it can provide a useful reference, which is for design or construction of pile foundation in similar projects in future.