Advanced Materials Research Vols. 255-260

Abstract: As a new dam type, Hardfill dam has been arisen recently. The suitable geologic condition of t Hardfill dam construction was analyzed based on considering its characteristics in this paper; it was also studied how to choose the reasonable impervious and drainage system to control the dam body and foundation’s seepage on a given geologic condition to make sure the safety of the project. On the basis of analyzing the foundation geologic conditions of many common dam types, two kinds of typical Hardfill dam foundation were put forward. The seepage field law of dam foundation was analyzed by dam foundation seepage discharge, uplift pressure and seepage gradient of some typical positions after setting reasonable impervious and drainage measures on the two kinds of dam foundations. It is indicated by the calculation results that the adaptability of Hardfill dam foundation is comparatively nice, and the safety of dam foundation can be ensured if appropriate impervious and drainage measures are adopted.

Abstract: The safety monitoring of the underground powerhouse is the effective means that people could know the state of operation and the security of the underground powerhouse. By the research of the safety monitoring, it can be acquired that including the various structures of the underground powerhouse, some basic knowledge of safety monitoring, the characteristics of the safety monitoring, the importance and difficulty of the monitoring and the principles of the safety monitoring. The safety monitoring in the future can work well to combine the theory with the practice, and that of the underground powerhouse can be smoothly completed.

Abstract: Concrete faced Rockfill dam (CFRD) is a safe and economical dam type in hydraulic engineering. The temporary dam body for flood control during construction period is usually used for CFRD, so the safety of temporary dam body during construction period is very important. Based on numerical simulation of the seepage field of the temporary dam body of CFRD using nonlinear FEM (Finite Element Method) under the action of flood of the river during construction period, the stability of the dam slope is studied. The effectiveness and applicability of the method introduced is certified through computation in the study on the practical project. The paper provides an effective analysis method for the study on the stability of dam slope of the temporary dam body of CFRD for flood control during construction period.

Abstract: The flow coefficient is an important factor in analyzing and computing the flow capacity of broad-crested ridge-free weir of low head hydroelectric key position. For determine the flow coefficient of the broad-crested ridge-free weir of low head dam accurately, this paper study on the rule of the flow coefficient change base on the Gudi hydroelectric station model test. The test show in the condition of the high submergence and complex upstream and downstream flow condition, the flow coefficient value that use empirical formula compute is big. The author proposes the correction formula according the empirical formula and the test result.

Abstract: Sloshing response of liquid in a rigid cylindrical tank with a rigid annual baffle under horizontal sinusoidal loads was studied. The effect of the damping was considered in the analysis. Natural frequencies and modes of the system have been calculated by using the Sub-domain method. The total potential function under horizontal loads is assumed to be the sum of the tank potential function and the liquid perturbed function. The expression of the liquid perturbed function is obtained by introducing the generalized coordinates. Substituting potential functions into the free surface wave conditions, the dynamic response equations including the damping effect are established. The damping ratio is calculated by Maleki method. The liquid potential are obtained by solving the dynamic response equations of the system.

Abstract: The 2-D water and sediment mathematical model which reflects silting in floodplain and scouting in main channel of over-bank flooding in the Lower Yellow River has been set up in this paper. Through carrying on 2-D water and sediment numerical simulation of the “96.8” typical flood, the author studied influence of over-bank flooding on flood travel and transverse exchange. The primary simulation results show that, adopting the over-bank flooding for silting in floodplain and scouting in main channel effectively guaranteed and expanded transverse exchange between floodplain and main channel and maintained the river channel vigor. This can relieve “secondary suspended river” states in the Low Yellow River to a certain extent; at the same time, the different magnitudes of over-bank floods have different effect of silting in floodplain and scouting in main channel.

Abstract: Taking the double-column pier as the research project, based on ABAQUS finite software, using the added water mass to consider the hydrodynamic pressure effect, considering the nonlinear of the soil and the concrete, building the hydrodynamic pressure effect model analysis of double-column bridge pier in deep water under earthquake actions, analyzing the hydrodynamic pressure effect on the relative displacement, acceleration, shear force, moment responses of pier and its hydrodynamic pressure coefficient under the earthquake. The results show that the earthquake hydrodynamic pressure changes the seismic responses characters of the pier, and increases the relative displacement and acceleration of pier top, and also increases the internal force of pier bottom. It is necessary to consider the hydrodynamic pressure effect in the bridge seismic design for comply with the actual situation better.

Abstract: On the basis of the field measurement, the characteristics of advance strata behavior are analyzed in the past filling working face and the advance support method is optimized in the roadway. The practical measure researches show that, because the paste filling supports the overlying strata of the goaf availably, the strata behaviors of 2351 paste filling working face in Daizhuang coalmine are not obvious; And the protective pillar bears a little load, The strata behaviors in non-production side are smaller than that in production side. The overlying strata gravity mainly acts on the coal wall in front of the face and the paste filling in the goaf. The value and main influence range of advance stress in front of the face is quite small and the main influence range is less than 15m. According to the advance strata behavior characteristics of the paste filling working face, the advance support of the track roadway is changed from 3 rows to 2 rows. And the support length of each row reduces from 20m to 15m. The advance support after optimizing can reduce the labor intensity greatly and improve the working efficiency of backfill mining.

Abstract: Numerical simulation and field measurement were carried out to investigate into laws of deformation and movement and the evolving characteristics of the plastic region around the roadway based on engineering conditions of deep soft rock roadway in Wangfenggang colliery, Huainan Mining area. The mechanism of controlling the surrounding rock stability of soft rock roadway in deep coal mine was demonstrated. The supporting of soft rock roadway in deep coal mine must be compatible with deformation and failure characteristics of surrounding rock, and it can keep the stability of surrounding rock. The combined supporting with high strength and prestress bolting-anchoring and integral surrounding rock grouting reinforcement can effectively control the surrounding rock deformation of soft rock roadway in deep coal mine. But every working step must be pay attention to sequence on the time and space so that it can play an integral supporting effect. Research results are put into practice accordingly and good control effect has been achieved.

Abstract: As for the multi-scale coupling phenomenon among substrate, bonding coat and coating in thermal barrier coating materials, the method of wavelet-based homogenization are used to convert the thermal equilibrium equation into a group of algebraic equations. Using this method, an operational matrix of integration based on the wavelet is established and the procedure for applying the matrix to solve the temperature and displacement are formulated. The results provide a theoretical basic for selecting coating thickness of thermal barrier coating materials in optimization design.