Applied Mechanics and Materials Vols. 353-356

Abstract: In order to avoid dig-hole pile excavation blasting effect the building structure safety and the life of residents around the project, take several controlled blasting technique measures in construction. Through taking reasonable arrangement of holes, delay time, specific charge, initiation ways and safety protection measures, and blasting vibration was measured and analized to guide blasting operations, finally the purpose of excavation blasting was achieved safely. The results show that several controlled blasting techniques used in the project are effective measures, not only ensure the good blasting effect but also control the influence of blasting vibration to surroundings, and provide valuable references to similar projects.

Abstract: Deep foundation pit support technology has widely affected the world, and well mainly talk about its application as a soil nailed wall in the engineering of underground garage foundation pit. Different ways of support were applied in different conditions to design construction examples, and then solutions of foundation pit support constructions were raised. So the engineering designing method has been proved correct and feasible.

Abstract: Because the pile foundation has the characters of high bearing capacity, small deformation and easy to construct, it is widely used in practical engineering. In order to verify the end-bearing pile loading capability, in this paper, the single pile vertical compressive static load test is used to the on-site measuring point in actual engineering test, and get the Q-S curve of the pile. FEM is used to simulate the test at the same time. The ideal elastic-plastic constitutive model based on Mohr-Coulomb failure criteria is used to simulate foundation soil. Some conclusions are obtained by using large scaled finite element analysis software ADINA to build the 2D plane strain finite element model and to proceed numerical analysis of the pile. Finally, the comparative analysis with the engineering practice is proceeded. It has the practical significance for the structure analysis of the single pile.

Abstract: Due to the upgrade and reconstruct of a high-piled wharf, the piling construction may cause the damage of the large diameter underground pipe of a power plant nearby. For this problem, a dynamic time-history analysis model was established using MIDAS/GTS program. Based on the analysis of the pile driving vibration and its propagation law, some parameters, such as the modulus of the soil, the Poissons ratio of soil, the action time of vibration load and the damping ratio of the soil that may have an effect on the response law of the soil, were studied. The study results not only serve as an important inference to the construction of this case, but also accumulate experience and data for other similar engineering practices.

Abstract: From the view of design, this paper have discussed some problems of design and application of deep cement mixing pile, and have analyesd the determination of single pile bearing capacity method, the checking of soft stratum, defects or errors existing in the calculation of cement mixing pile of composite foundation settlement, and have put forward some suggestions for improvement.

Abstract: Joints information in specific rocky slope free face could be collected by modern untouched measure technology in engineering. Possible key blocks are displayed after system analysis. Experiment spatial blocks and structural planes dimensional angles can be changed with the variable angle space test platform, lead to reaching the target that position of spatial blocks are simulated, which suggests the secure stability of spatial blocks. Least square data fitting method is used according to experiment data-the two slide angles and failed mode. Security assessment is proposed and numerical method is applied to testify the experiment results.

Abstract: A series of tests are conducted to get the physical composition, physical form and the soil-water characteristic curve in different dry density of three typical composite unsaturated soils in west Sichuan. Test data shows that the variation of physical composition, particle size and dry density can result in great change of soil-water characteristic curve. The bigger the dry density is, the more hydrophilic mineral the soil has, the more gentle the soil-water characteristic curve is, and the higher its residual moisture content is. In addition, under the same water content, matrix suction decreases with less clay content and more content. For the three typical composite unsaturated soils, with relatively bigger water content, the change of soil-water characteristic curve resulting from variation of dry density is less, but with the water content getting smaller, the change becomes clearer.

Abstract: After hundreds years or even a thousand years of vicissitudes, the earthen sites are destroyed seriously. Protecting these cultural relics has great historical significance and practical value. The protections of the earthen sites include two aspects which are chemistry and physics protection at present. Compared with chemic protection, the structure stability is more important. So the stability reinforcement used bolt is researched for many scholar. Combined the reinforced project of Gaochang earthen site in xinjiang province, and directed toward the new type bolt of geo-filament, the article introduced the construction technology of the geo-filament bolt; in addition, the numerical comparative tests in typical soil medium were implemented and compared the bearing capacity of bolt from the different affections, and the working mechanism for bolt pulled-out test was revealed quantitatively by the overall course simulating analysis. According the test results, the surface state affects the anchor force obviously; the length of bolt is feasible from 0.8-2.0m. the geo-filament bolt is proved to be an excellent material which is used in the walls reinforcement of earthen sites, and it has many typical characters which are advanced technology, novelty techniques and construction facility. Because of that, the new research will play an important part in guiding us to protect the earthen sites.

Abstract: The bearing capacity of slime friction pile based on the Mohr-Coulombs strength criterion couldnt make full use of the potential strengths ability of rock-soil. But the double shear unified strength theory can depict really the bearing characteristics of rock-soil because it can consider the effect of intermediate principal stress comprehensively. On this condition, based on the Mindlins displacement solution and the double shear unified strength theory, a calculated formula of bearing capacity was proposed for the slime friction pile, and then the distribution regularities of lateral friction-resistance force for the slime friction pile were discussed.

Abstract: A landslide model test under the artificial rainfall was built according to the rainfll-induced landslide in Fujian mountainous area. The rainfall intensity, the slope types (mainly on vegetation coverage) and the grade of side slope were the main factors in the test. The rainfall threshold of rainfall-induced landslide on shallow bedrock was obtained from the test. The relationship between the cumulative precipitation and slope angle and slope surface types was analyzed from the orthogonal experiment by multiple regression analysis. Results show that most slope failures are caused by the infiltration of rainwater. Conclusion show that when the slope angle and vegetation cover are given, critical hazard threshold can be predicted, and the corresponding landslide sliding time can be gained by combining with the rainfall intensity.