Ning Lian Lu Guannan Toll Stations Pile Testing And Pile Capacity Study,

According to the exact example of a pile foundation work, the conception of single pile vertical ultimate bearing capacity, the basic theory of the pile and earth model, and the theory of pile's ultimate bearing capacity are introduced in this article. At the same time, it is asserted that the strength of the foundation layers and the quality of the piles are the main factors which directly decide on the single pile's bearing capacity. Further more, the static loading testing method and the high strain dynamic testing method which are practiced to obtain the bearing capacity of a single pile are also introduced in this article. In the practice, the two methods are supplemented each other and combined to be used.It is generally thought that the static loading testing method is one intuitionistic, liable high precise single pile bearing capacity testing method. Commonly, in order to get the single pile's bearing capacity and settlement, the testing method is practiced under the vertical compressing load conditions, just like the pile's practical working conditions. But the judgment of the pile's integrity can not be obtained in this testing method.The high strain wave matching testing method is one of the dynamic testing ones. Based on the transmission theory of elastic wave, the one-dimension linear formulation is set up. Under some hypothesized conditions, the formulation can be settled, thus the ultimate bearing capacity and the conclusion about the pile's integrity can be got. In the practice, the wave matching mathematic model is generally used in the high strain testing method. One of the drawbacks of this testing method is that the settlement of the piles can not be known.In this article, the two testing methods' conclusions about the practical pile foundation work ultimate bearing capacity are given. So many reasons why the piles' ultimate bearing capacity are not fit to the designed bearing capacity and why the engineering accident happened are carefully analyzed. According to many years' working experience at this domain, the author pointed out that those working processes, such as geotechnical investigation, design construction, construction supervision and examining directly decide on the piles foundations' quality. So, in order to assure the engineering quality of the piles, we should adapt the scientific managements methods to harmonize the different parts of the geotechnical engineering, act on all kinds of norms and regulations, as well as improve the engineers and workers' expertise level.