Applied Mechanics and Materials Vols. 501-504

Abstract: According to the investigation and survey of the service condition of the double-block ballastless track in China, the breakage rate in the rich rainfall areas or the poor drainage lots of double-block ballastless track runs much faster than the dry areas. Some typical diseases, such as sleeper loose, contact loss between sleeper and roadbed slab, will lead to water still in the sleeper void. Free water underneath the sleepers would become dynamic water with certain pressure and flow rate under the high speed and high frequency action of train loads. Dynamic water is able to accelerate crack growth rate and scour the bonding interfaces between sleeper and roadbed slab^[1,, affecting the safety ,durability and riding quality of track structure. It is meaningful for us to research on sleeper loose of double-block ballastless track under the coupling action of train load and dynamic water and prove the mechanism of sleeper loose in double-block ballastless track under action of dynamic water. Calculating the value of water pressure and velocity of flow and then providing references for study on the hydrodynamic characteristics.

Abstract: The cut-off wall of Xiabandi project commenced in April 2006, cutoff wall and curtain grouting project were completed in November 2009, monitoring equipments for dam foundation seepage and cutoff wall were installed in June 2009. Through the analyzing of the observational data from 2006 to 2010 and the statistical date of cut-off wall section deflection, the stress and strain values and water level changes during water storage, the characteristics of cut-off wall deformation under construction and in the storage are fully and accurately reflected, while the feedback to guide the construction with the monitoring information has also played an active role.

Abstract: By changing artificial-reefs meeting flow angle, Use the CFD imitate three-dimensional flow field under the compaction of constant flow, and analyze the effect of back eddy flow field quantitatively. The results show that, with the reduction of the angle of the meeting flow, the length; height; width of back eddy has the tendency of becoming small; when the angle become Ninety the effecting of the back eddys flow field is the best.

Abstract: Suction jet scheme has brought forward sediment suspension transport work parameter in the scheme of water and sediment transporting and sediment adding in discharge water before the flood season of Xiaolangdi Reservoir. Suction jet system starts suspended sediments as per 1 natural bottom slope of Xiaolangdi Reservoir while jet pump eject muddy water, which forms into density current and transport forward, and makes longitudinal deposition in the process of sediment transport. Transport distance shall be 1,264~1,903m while 50% longitudinal attenuation of sediments as effective transport distance. Bottom slope of sediment deposition is reduced to 6.7 with obscure longitudinal attenuation of sediments and can transport to longer distance.

Abstract: According to the current situation of water control project, the existing problems and the audit opinions of superior administrative departments, water control pivot of the West Bridge over the Aksu River is in urgent need of risk-elimination and reinforcement. Based on hydraulic model test, discharge capacity and sand transporting effect of floodgate and scouring sluice as well as design reasonability of energy dissipation and erosion control structure at pivot downstream have been observed and measured in risk-elimination and reinforcement of the West Bridge. It is indicated in experimental research, compared with the designed flow and checked flow in the design, the measured water levels of the floodgate are 0.43m and 0.47m lower, and measured water levels of scouring sluice are 0.12m and 0.15m lower; opening ten holes of the floodgate can take significant sand transporting effect, while scouring sluice makes insignificant sand transporting effect; it is suggested that design institute shall take erosion control measures into consideration within 100m to the floodgate tank.

Abstract: In real sea state, Ocean energy devices to work hard to stabilize, or even destroyed. Based on Airy wave theory, Movement and force of heaving cylindrical wave-energy converter (WEC) was analyzed under the complex marine state. Then setting the South China coast as the environmental background, and simulating and computing the motion response of the buoy and the mooring system under various sea conditions. The computational data show that complex mechanical response was happened and the mooring system (SM) has excellent mooring performance. The research results have practical significance for heaving cylindrical WEC survival design under real sea conditions.

Abstract: Based on the characteristics of slope failure induced by rainfall, from the point of view of moisture migration and combining unsaturated soil mechanics, the characteristics of moisture migration in slope under different rainfall intensities were analyzed by finite element method. The results reveal that under rainfall, the pore water pressure in slope is in layered distribution, and at the bottom of slope, the pore water pressure is the highest, the top is lower and the middle is the lowest. The volumetric water content is in nonlinear distribution and the degree of nonlinear in unsaturated area is higher than that of the saturated area. The permeability coefficient of soil rises with the increase of rainfall intensity, and when the soil is saturated, its permeability coefficient is saturate permeability coefficient.

Abstract: The combination weighting approach of subjective and objective is applied to calculate the weights of each index to evaluate the hazard degree of navigational environment in ports, which can both reflect the opinions of experts in the field truly and utilize the statistical information of sample fully. Based on the weights determination, the distance function modelling is used to make an overall assessment of the navigational environment. According to the application of the model, it is convenient and quick to make a comprehensive assessment of the navigational environment in several ports using this model and the evaluating result is of stability and reliability, which can provide a theoretical basis for the strategy determination of port authorities, maritime administrations and officers on board.

Abstract: For deep-sea diking engineering, the water is deep, wave is high and stream is torrential in the erection stage, so the construction difficulty is very high. In this paper, the authors prove the feasibility of realizing the deep-sea erection by the pioneering dike from aspects of structure of the pioneering dike, construction equipments and operation procedures, etc., utilizing features of the pioneering dike, such as small body, flexible and fast construction, and capacity to fully utilize the conditions of falling tide.

Abstract: Xiabandi hydraulic engineering is located in southern Xinjiang Pamirs, with the characteristics of" three high and one deep ", namely high-altitude, high seismic intensity, high slope and deep overburden^[. Therefore, treatment of deep overburden dam is a thorny problem, deal with problem of dam foundation deep overburden for quality and safe operation of the project is very important. This paper sitting under the hydraulic engineering project, according to the difficulty of construction, seepage effects and costs and other standards for deep overburden seepage form a comparison study, the final selection of a combination of vertical seepage curtain wall forms to solve the deep cover layer impermeable problems and provide valuable experience for future similar projects in design and construction^[2-4].