Applied Mechanics and Materials Vols. 438-439

Abstract: Xiping iron smelting site is the fourth installment of the national key cultural relics protection units. The protective house is surrounded by water, with its base on expansive soil. With the influence of the slide of dams during the flood season, a lot of cracks occur in the protective house and its surrounding, resulting in severe potential danger to iron smelting site. The effect of expansive soil, steep slope reservoir and rainfall on house deformation is analyzed, qualitative and quantitative analysis on slope stability is conducted, results indicates that the protective house will be damaged under rainstorm or continuous precipitation, basic stability will be lose under natural condition.

Abstract: In this study, prototype site cyclic loading experiments were carried out on the reinforced cushions constructed by geoocell and geotextile to confirm the stability of reinforced ground. The experiment reinforced grounds by some methods are constructed continuously in the site. The cycle loading is given by the load vehicle on the ground. As the results, the reinforcing effect of combination geocell with geotextile cushion was similar to that of combination geocell with geogrid cushion.

Abstract: Static pressed pile in the sand is a complex process. In this paper, strain of each point in the process of model pile sinking was measured by lab model test, the relationship of stress and strain of piles and the corresponding stress coefficient are made by semi-numerical and semi-analytical mathematical methods, the distribution of confining pressure and friction are built, and the calculation of sinking pile resistance in the process of construction is given out. The result provides the directive reference for the design of static pressure pile.

Abstract: Based on tangent-modulus method of undisturbed soil, rigid pile composite foundations with different cushion thickness, different cushion stiffness, different pile length and different pile diameter are studied. P~S curve and load sharing ratio of pile in different composite foundations are compared and several laws are summarized. It will give guidance to the setting of cushion thickness, the selection of cushion and the design of rigid pile.

Abstract: There are a lot of factors that influence the bearing capacity of composite foundation, and the relationship between them is complex and nonlinear. Based on study of main factors that have great influence on bearing capacity of cement-flyash-gravel (CFG) pile composite foundation, the least squares support vector machine (LS-SVM) model of bearing capacity of composite foundation was established. The results show that the model has excellent learning ability and generalization and can provide accurate data prediction only with fewer observed sample. It is proved that the new method is a promising method for the determination of bearing capacity of CFG pile and other rigid piles composite foundation.

Abstract: In order to calculate the ground movement induced by displacement piles driven into horizontal layered soil, it is simplified to an axisymmetric problem. Then the vertical and horizontal ground movement functions were deduced based on stochastic medium theory. The vertical ground movement is a normal distribution function, while the horizontal ground movement is an exponential function. Utilizing field measured data, parameters of these functions can be obtained by back analysis. The example indicates that the stochastic medium theory is suitable for calculating the ground movement in pile driving, and there is no need to consider the constitutive model of soil or contact model of pile-soil interface in calculation. This method is fairly applicable in practice, and can provide a reference for related research.

Abstract: Based on the compaction effect of the gravel pile, the thick-walled tube model is established. Considering the gravel pile and pile materials with different properties of tension and compression of soil pile in the process of expansion, the influence of intermediate principal stress to improving the bearing capacity of foundation in the process of expansion, we use the planar axisymmetric double shear unified strength theory and present a gravel pile ultimate bearing capacity of single pile composite foundation unified expression. The theory study of gravel pile composite foundation and engineering practice has a certain guiding significance.

Abstract: This paper determines the bearing capacity of pile and shaft resistance by the curve match method of high strain dynamic testing. By the comparison of bearing capacity of pile between the testing results of static loading and dynamic high strain, the reliability and surveying precision of the curve match method is analyzed, and the error sources and reasons are explored, to reasonably determine the design parameters of pile foundation engineering.

Abstract: A prediction method of bearing capacity of CFG pile composite foundation was presented based on that support vector machine and corresponding prediction model was set up. To obtain the model coefficients, 18 groups of test data of CFG pile composite foundation were trained, the training value conforms well to the test value. Then the model was used to predict another 4 groups of test data. The result showed that the prediction value was close to the test value. The theoretical analysis and practical example indicated that the prediction method of bearing capacity of CFG pile composite foundation based on support vector machine is accurate and reliable.

Abstract: This paper introduces the "Levels of anchor cable +Bored piles +Net shotcrete combined support plans application in deep foundation pit engineering at Zhengzhou north freight marshalling station. Construction practice and monitoring data show that the engineering supporting design and construction have got an ideal effect, to ensure the safety of the north Ring Bridge and the railway line. It has a certain guiding significance to similar municipal engineering.