Applied Mechanics and Materials Vols. 170-173

Abstract: The seawater intrusion is a kind of comparatively common natrual geological disaster around the coast area. In order to solve this sort of geological disaster, scholars both home and abroad have been doing quite a large amount of work to find out the cause of the disaster and the methods of its prevention. Among all of these work, the research of Yantai seawater intrusion comprehensive governance is one of the most typical. We take Yantai for instance, studying both engineering and management measures of the prevention of seawater intrusion, while at the same time exploring and discussing the pattern of the prevention of seawater intrusion by integrating "point, line and all the aspects" comprehensively, which produces quite outstanding results.

Abstract: Dam deformation analysis is one of the main tasks in dam safety monitoring. Regression analysis model is often used in dam deformation analysis in early days. At present, the statistical model, which divides the dam deformation into three parts, hydraulic pressure component, thermal component and ageing component, according to the causes of deformation, has been widely adopted in dam deformation analysis. The BP neural network model and the merging model based on BP neural network algorithm of dam deformation analysis are mainly discussed in this paper, and finally, the four models mentioned above are calculated and analyzed according to a specific project instance. The precisions are respectively ±1.19mm, ±0.38mm, ±0.34mm, and ±0.28mm for single linear regression model, statistical model, BP neural network model and merging model. So it is shown that the merging model is better than the others according to the results.

Abstract: The physical properties and characteristics of absorption and emission spectra of Yb: YAG crystal are analyzed in this paper. From the rate equation of quasi-three-level system ,We derive the rate equations of diode-pumped continuous work-end-pumped solid state laser and a theoretical analysis and optimization design for continuous LD end-pumped lasers are given.

Abstract: Abstract: By means of two reference sites, site effects in 29 stations of Shanxi Province are analyzed by using 2008 Wenchuan earthquake data according to adopting traditional ratios method. Because site predominant frequencies getting from all kinds of computations have higher reliability, suggestion is made that in order to reduce loss producing from construction resonance in earthquake, natural frequencies of future constructions in above sites should keep away from site predominant frequency as possible. Computational results show Shanxi areas arises strong site effect in earthquake, this has close relationship with geological structure, formation lithology and strong new structural movement, etc.

Abstract: The thesis probed and introduced that the selecting of programming language and the choice of monitor analysis mathematic model trussed on multiple models according to the merit and demerit of the selected mathematic model and combining the computer language feature so that the most effective mathematic model was selected in monitor data analysis and the rationality of data analysis was increased in the weaving of dam safety monitor analysis soft ,meanwhile, it increased the precision of prediction, and it made that common operating staff could do that in operating and using.

Abstract: Artificial recharge using outside diversion water is an effective method to solve the water resources shortage, but it’s necessary of groundwater quality analysis during the recharge process. For the parameters acquisition of artificial recharge, a field infiltration test had been taken with the Hutuo River bed, the ions variation had been tested. The results show that, Cl-, SO42-, F- increase but NO3- decreases during the recharge process, then get back after the recharge termination; considering mixture is main factor of Cl- variation, the proportions of different water resource had been calculated, the proportion of recharge water increases during artificial process and decrease after the recharge termination, hysteresis exists between different sampling wells by the responding time and peak time.

Abstract: We know that the dam materials have been determined in the process of the dam reinforcement, in this case can only through the upper wall on ways to reduce the infiltration line. This paper was based on this combined with the reinforcement process of a main reservoir explaining that the scheme selection about using drainage edges to lower infiltrating line of the body, and through the application of this technology, showed it is a good way to lower the infiltrating line of the dam, and eventually an effective and simple measure to reinforce dams.

Abstract: The paper concentrates on the posture of airliner landing onto water in slide decelerating stage. For different angles, the difference equation is constructed to find the posture of airliner by using solid-fluid coupling, momentum conservation, motion equation and pressure drag. The results show that impact acceleration is inversely proportional to the sliding distance, the impact of stormy wave can make airliner out of balance, and course angle is 80 can minimize the chance of rollover.

Abstract: This paper used AQWA software to research the nonlinear motion characteristic of heave-pitch coupling of classical Spar platform in regular waves. With classic Spar platform as an example, the wave amplitude and periodic changes’ effect to the nonlinear motion behavior of coupled heave-pitch is researched. After calculation, the critical periods corresponding to the different incident wave amplitude are obtained, based which, gets the instability parameter domain of coupling resonance of platform in the wave period-amplitude plane. The results in this paper show that the heave-pitch coupled resonance of platform depends on the wave amplitude and the ratio of the natural period of heave and pitch, and the incident wave period.

Abstract: According to the structural character of Powerhouse Dam of Feilai Gorge Multipurpose Project, this paper analyses the deformation regularity of the dam top of a typical dam section with the plane finite element method combined with strength reserve method. Then the horizontal deformation of the dam top of combination of different water level has been obtained. According a binary quadratic regression the model of the relation between the horizontal deformation of the dam top and the water level has been based, and the concrete data of this dam section has also been studied out. When the dam section runs and is being observing practically, these monitoring indexes of horizontal deformation can be consulted and provide important basis for monitoring the safe operation of the dam.