Study And Application On Nonlinear Settlement Computation Of The Soil Foundation Based On In-situ Testing

The predicting of settlement is very improtant in the design of foundations,and the proper evaluating of settlement can guarantee the safety of building structures or save money. Therefore, it have to compute accurately the settlement of the building and make it is within the scope of the building allow. The soil calculation parameter is inaccurate because of the special soil structure, so general settlement calculation is not solved well now.Aimed at the merits and demerits of traditional settlement calculation method, Yang Guang-hua proposed a new settlement calculation method-undisturbed soil tangent modulus method. Which was based on in-situ plate loading test P-S curve. It can better solve these problems in the calculating foundation settlement. The problem was, such as the parameters were not obtained accurately and it was not revealed the nonlinear for the foundation soil. This new method was used for settlement calculation and get more accurate results. The undisturbed soil tangent modulus method is based on in-situ plate loading test P-S curve,but the work of the in-situ plate loading test has great capacity and time is long.And it's no way to obtain accurately the strength and deformation parameters of the deeper soils. In order to generalize the undisturbed soil tangent modulus method, this paper based on the undisturbed soil tangent modulus method study the settlement calculation method to the foundation.First, the research situation of the settlement calculation method to the foundation and a detailed analysis about all kinds of methods that were used at present were given in this paper. Then an evaluation about these methods'advantage and disadvantage was made. And the reason that the value of calculating settlement was not accurate was indicated.Secondly, a comparatively systemic summary about undisturbed soil tangent modulus method was made. And then, the parameters of calculating settlement for using the new method was discussed.Then,the basic theories frame of the pressuremeter test and the engineering application of it's results was elaborated. The pressuremeter test can go the test in the different depth, and the accuracy is high, the equipments is easy and convenient, test time is short.By the measured data comparison of the pressuremeter test and the in-site load plate test to make sure that the relations of the undisturbed soil deformation parameters that ditermined by the two tests.Finally, under the condition of certain, a method of evaluating the loading plate test setttlement of foundation soils by pressuremeter test result is proposed.and through the in-site test to verify its rationality.Then, using the pressuremeter test ,operate in brief and easily,to replace the loading plate test that operate time-consuming, and go forward to ditermined the undisturbed soil tangent modulus. The foundation nonlinear settlement undisturbed soil tangent modulus method was adopted to compute the foundation settlement,and the calculation parameter was provided by the in-site test. Through the measured resultes and the in-site test of the engineering to verify the rationality of this method.