Applied Mechanics and Materials Vols. 170-173

Abstract: The anti-seepage measures of a high earth rockfill dam built on the foundation with a deep overburden affects the stability and safety of the dam greatly. Nowadays there are few researches on this area both at home and abroad. On the basis of the finite element seepage analysis of the Pubugou high rockfill dam in which core walls and two cut-off walls are designed as the anti-seepage measures, the real seepage behavior of the seepage field is obtained in this paper, as well as the seepage characters of the seepage field under different arrangements of the cut-off walls. The conclusions have a certain referential value for the design of the anti-seepage measures for the similar projects with the foundation of a deep overburden.

Abstract: Continual overdraft of groundwater resources for many years has led to continual declining of groundwater level in large scale areas in Shijiazhuang. Groundwater in Shijiazhuang City has been contaminated in varying degrees during its development and utilization due to no appropriate protective measures taken for groundwater resources. Groundwater pollution is severe in some areas, which poses a threat to sustainable utilization of groundwater resources and economic and social development. To protect groundwater resources effectively, a study on the impacts of general planning implementation on groundwater resources was carried out, including groundwater pollution sources, groundwater quantity and groundwater quality evaluation. The research results could provide scientific reference for development planning and sustainable utilization of groundwater resources of Chengting new district.

Abstract: Large-scale water resource system with multi-water resources and multi-users consists of several independent supply and drainage network systems. It is hard to solve the problem well of large-scale water resource system with traditional planning method. We model the problem of optimal allocation of water resource using the principles of biological evolution, and eliminate the inferior by judging the optimization degree of each generation individuals, then produce a new generation, thus the optimal allocation of water resource is accomplished through iteration repeated. The disadvantage is that MOGA solution out of the quasi-global optimal solution, rather than the true optimal solution.

Abstract: A finite element procedure of a four-node rectangular flat shell element (FSE) is programmed for structural analysis of steel penstocks. The influence of axial constraint and support settlement on the internal forces of the steel penstocks is investigated. It can be concluded that the FSE is suitable for thin shell structures of steel penstocks and can achieve satisfying accuracy. The axial constraint caused by rest piers would remarkably increase the axial internal forces along pipeline, while the influence of support settlement on the internal forces of the steel penstock is limited, and so is the increment.

Abstract: Shifosi reservoir is a collection of flood control and urban water supply function in one of the plain reservoir. After reservoir water built, the surrounding residential and agricultural cultivated land produced serious phenomenon of immersion. In order to solve the environmental geological disaster problems caused by Shifosi reservoir retain water, this paper uses the fuzzy comprehensive evaluation method to evaluate the immersion. It used fuzzy math theory and analysed the produce condition of reservoir immersion, then built the immersion grade evaluation target system and standard value , and maked out the estimating index weight with analytic hierarchy process, which influence immersion grade. According to the evaluation results, puts forward well pumping water solution, and finally achieve control ling the phenomenon of immersion ,at the same time pumping groundwater can be as Shenyang water supply sources. To achieve the effect of kill two birds with one stone. On this study of Shifosi reservoir immersion to solve engineering problems and provide the scientific and feasible basis. This study selected of evaluation factors immersion degree. Evaluation standards to similar problems of great reference value, and for immersion degree of evaluation has provided a new way.

Abstract: This paper introduces the field monitoring results of the connection earth dam in Chaozhou water supply pivot project. In this project, magnetic lamination-settlement measuring instrument, which is installed 3 ones in four sections each, is used to measure the settlement of the Xixi earth dam. Based on the analysis of monitoring data and simplified calculation, we get some useful conclusions. The magnetic lamination-settlement measuring instrument can directly measure the absolute value of deformation without the need to correct, calculate or measure benchmark. It’s more accurate than pipe type settlement instrument. In connection earth dam, conjoined mixing pile for resisting slippery has an effect of constraint and anti-seepage on the dam, which has played a good effect of controlling the dam settlement and the settlement difference between the ship lock and the connection earth dam. Vertical displacement of earth dam is very sensitive to the influence of factors such as water level. Settlement value of earth dam during operation is about 10.6%~38.7% of total settlement and settlement value of the head bay in ship lock during the operation is about 11.4% ~ 23.8% of total settlement.

Abstract: In the impervious system of dam construction technology without foundation and the cofferdam, the cut-off wall, seepage curtain or high-pressure jet, oblique wall, etc. do not exist. It does not require pumping pit and need a lot of pit excavation. the technology can save a lot of investment and greatly speed up the construction speed, shorten the construction period. To study dam construction technology without foundation, the method is technically feasible, and no adverse consequences, completely meet the project needs.

Abstract: The water passageway structure of pumping station is both mass concrete structure and complicated structure. Cracks always appear in these areas during construction period. It will shorten the building life, and endanger the safety of pumping station. Three dimensional finite element method is adopted to simulate the temperature field and stress field of pump station in construction. The considering loads include gravity, temperature, autogenous volume deformation, and creep. The temperature and the first principle stress duration curves of easily cracking area are analyzed in different cases. After optimization of different temperature control measure, the tensile stress of different areas in early age or later age can be controlled lower than tension strength, and the cracking prevention safety factor can be raised. It is found that pipe cooling, surface insulation, pouring intermission, structure constrains can change the tensile stress obviously for pumping station. The influence of these factors is separately concluded.

Abstract: For slope risk analysis of tailings dam, the current research focuses on treating physical and mechanical parameters of tailing materials as the basic random variables. The influence of the external natural random factors is considered little. In practice, the slope stability of tailings dam is influenced by not only their random material parameters but the various natural factors including the changes of water level and the seismic intensity size. As a rule of thumb, there might be heavy rains before the earthquake. Therefore, it is necessary to comprehensively consider the slope risk of tailings dam under the coupling effect of rainstorms and earthquakes. Aiming at this problem, reliability theory was employed in this paper to study the influence under both rainstorms and earthquake actions. In this project, the slope risk analysis of tailings dams is evaluated under natural multi-random factors.

Abstract: Rainfall and the water leak frequently causes the unsaturated loess slope landslide and the foundation destruction. The theoretical analysis was accomplished, then a two dimensional water seepage calculation model for loess foundation was established. It realized the forecast for the water content change of loess soil. Combined with an example, the calculating program was compiled by Matlab. The result confirmed the effectiveness and rationality of the method and model.