The Research Of Transient Surface Wave Test Technique Applied In Gravel Pile Compound Foundation Bearing Capacity

Now there are many inspecting method of compound foundation bearing capacity, but most of them are base on the static load test or the original place test to obtain the compound foundation bearing capacity. These methods are time-consuming and laboursome, and they can't give the compound foundation a wide-ranging, integral inspection and evaluation. So a new and fast method that applying Rayleigh surface wave to inspect the bearing capacity of compound foundation is given in this thesis. In the thesis domestic and foreign relation model of standard penetration blow count and shearing velocity, standard penetration blow count and deformation modular, shearing velocity and foundation bearing capacity are analyzed. On base of these analysis a new calculation model that applying Rayleigh wave velocity to calculate the stress ratio of pile and soil between piles is established. Because of the difference of region and soil character, the new model own three branch model, ie, Japan Model, Wuhan Model, Xia Liaohe Model, in three different conditions. Associating example, the influence factors of the stress ratio of pile and soil are discussed, especially the replacement rate, the modular ratio of pile and soil, deformation modular of gravel pile, Reyleigh wave velocity of soil between piles are given more effort. The analysis show that the influence given by the area replacement rate is very little, while the modular ratio of pile and soil is a important influence factor. The research about the deformation modular of 17 gravel piles show that the variation rage of gravel pile deformation modular is little, so long as the construction quality is good. So the deformation modular of soil between piles, that is the Rayleigh wave velocity of soil between piles is the capitally influence the sampling of n. According to the calculation formula of the ratio of pile and soil of compound foundation bearing capacity, and base on the calculation formula of the ratio of pile and soil given in this thesis, the relation model of Rayleigh wave velocity and gravel pile compound foundation bearing capacity is deduced. Three models, ie, Japan Model, Wuhan Model, Xia Liaole Model about gravel pile compound foundation bearing capacity are established. To verify the three model established above, the calculation results are contrasted to the result of static load test base on such three yard as Langfang City Law building, Sanhe City Huatai Garden building B, Sanhe City North Pass. The contrast result show that the methodgiven in this thesis is available. Thus, it offer a new method to inspect the compound foundation. Contrast to such original place test method as static load method and drilling method, the method that applying transient Rayleigh surface wave to inspect the compound foundation own many virtues as low cost, high efficiency, non-destruction, and it also can save much labour and effort. Furthermore, it can implement the large-wide and comprehensive inspection and evaluation of compound foundation bearing capacity. Consequencely, it break the old situation that the inspection of compound foundation bearing capacity only can be partial and selective.