Applied Mechanics and Materials Vols. 212-213

Abstract: In order to control the seepage and eliminate the adverse effects, influencing factors of drainage in engineering are discussed in this paper. The drainage holes are simulated by rod element to study the influence of drainage performance on angle and length. Compared the drainage performance of drainage galleries in different location, the optimal assembly is obtained. Meanwhile, drainage performance is analyzed by different permeability coefficient and anisotropy of rock and soil mass. The results show that: (1) Drainage flow of small angle and short drainage hole is close to big angle and long one, the small angle flows more than the big angle when increasing the same length. (2) Shallow drainage galleries can significantly drop the free surface and the deep one can greatly decrease the pore water pressure. Drainage galleries built at the upstream side and bottom, as the optimum assembly, can enormously change the seepage field. (3) For anisotropy materials, the horizontal drainage performance is better than vertical when Ky/Kx decreases. On the contrary, vertical is superior to the horizontal. Increasing vertical permeability coefficient is benefit to drainage.

Abstract: In order to realize real-time leakage (online) diagnosis, through correlation analysis of the network leakage and pressure variation, using the established microscopic model as the basic hydraulic analysis model, using the position of the network leakage point and the water of leakage point as the variables, using minimizing difference of the network pressure points monitoring value and simulation value as the target when leakage occurs, establish inverse transient leakage location of water supply network model based on genetic algorithm. Finally through the two modes of leakage verification, the result shows that this model can effectively achieve the network leakage location and quantitative.

Abstract: Pollutants of urban rainwater runoff on water environment as well as the influencing factors are reviewed. By comparing with combined sewer overflows (CSOs), the paper thinks that urban rainwater runoff pollution control is necessary. Four months road runoff and Combined Sewer Overflows quality monitoring was carried in Luoyang, where indices included suspended solids(SS)，chemical oxygen demand(CODcr), dissolved chemical oxygen demand, Ammonia nitrogen(NH3-N) and total phosphorus(TP).The results showed that the concentrations of pollutants of Combined Sewer Overflows(CSOs)were higher than that of street runoff. Concentrations of pollutants in initial flush were very high, but they descended gradually and approached to the stabilization after a period of flushing. The main pollutants were SS, CODcr and NH3-N. By analyzing the correlation between SS and CODcr, and contrasting the content between total CODcr and dissolved CODcr, it inferred that SS was the main contribution to CODcr. The initial split-flow is suggested to handle the heavily polluted runoff.

Abstract: In order to analyse the feasibility of the original design of a drainage system in a tailing pond under design conditions, hydraulic model experiment should be conducted for discharge security according to the standard. This paper mainly discusses the optimal design for the drainage well and drainage tunnel in the drainage system. As aerification is rather severe in the drainage well, paroxysmal jet flow phenomenon appears at the well outlet flume section. To alleviate this situation, a stream-stabilized slope board, flow-diverted board, larger energy dissipation space and other more measures are needed to improve the flow state and increase the spilling capacity of the drainage well until it can satisfy the design requirement.

Abstract: The drainage ditch is important for the plain reservoir, the water table in the dam foundation outside the enclosed dam can be lowered by the ditch, and some leakage water can be pumped from the ditch return to the reservoir. So the design of the drainage ditch is the key to the plain reservoir. The finite element method is used to investigate the effects of the position, width, depth and the relief well of the ditch on the drainage effects. The results show the drainage flow is proportional to the depth of the drainage ditch, and is inversely proportional to the distance between the ditch and dam, and the relief well can increase the drainage flow and lower the grounder water table.

Abstract: The ShiQiao Reservoir was built in the 1950s, whose main functions are irrigation and flood control. With the increasing number of downstream agricultural water, the contradiction is increasingly prominent between pettier beneficial capacity and the raising downstream agricultural water; at the same time, due to the disrepair of spillway and the increase of upstream inflow, the original spillway flood discharge capacity cannot meet the requirements for flood control. On the basis of systematical investigations of engineering geology and hydrogeological, an effective method is proposed for plain reservoirs to solve these problems. The method is, by improving the weir crest elevation and widening spillway to address the inadequate of beneficial capacity and the low standard of flood control spillway. Through the validation of analysis and calculation, this method is feasible and economical. It fundamentally solves the problems of ShiQiao Reservoir, and ensures the safe operation of this reservoir.

Abstract: the amount of water and sediment reduce obviously in Ning Meng reach because of the influence of the regulation of Long-Liu reservoir in upper of Yellow River、rainfall and production and living use water, especially the time reduce of large flows and the growth of small flow duration time, resulting main channel siltation and atrophy severe in the Inner Mongolia Reach, lower bankfull discharge, the main channel flooding capacity decreased when the great flood of water level rise, resulting in the increase of the river's ice flood control pressure. The study will provide technical support for flood control decision-making.

Abstract: Floods are indeed one of the most serious natural hazards for human societies, especially in China. Future flood variations are an issue of great uncertainty, and the risk analysis of floods is absolutely necessary. Based on the fact that floods are influenced by many factors, the occurrence of floods is fuzzy for our perception. Therefore, the interior-outer set model (IOSM) is introduced to calculate the flood fuzzy risk. The risk calculated by this proposed model is a particular case among imprecise probabilities, called possibility-probability distribution (PPD). The feasibility of this method is verified by citing annual maximum flows in Longmen station of Yellow River main stream as an example. The results show that this approach could give a better result to support flood risk management.

Abstract: To reservoir flood control operation of the multi-objective decision making. The proposed reservoir flood control operation. Then, according to the model, the weight of goals with realistic and easy to program have been obtained by iterative calculation. According to the weight goal has been to meet the goal of accuracy the value of integrated decision-making and fuzzy partition, and according to the results determined the type of the decision-making and an order. The example shows that the multi-objective decision making model may use in the reservoir the flood prevention dispatch practice.

Abstract: With the actual engineering as an example, the content and method of flood impact assessment in the river management of gas station construction project within the scope of river management was discussed in this paper. Construction project to review the job has certain referenced effect, so that the flood control evaluation can reflect the effect of the construction project on flood control, in order to take measures to ensure the safety of river flood.