To effectively judge the vibrational stationary state of hydropower units, the whirling characteristics of the rotor vibration and the evaluation method of stability of shaft vibration were studied. The theoretical expression of instantaneous whirling velocity was derived, and the characteristic parameters of whirling velocity were analyzed. A holographic whirling velocity analysis method for shaft vibration was proposed. The whirling characteristics indicators and vibration stability evaluation index of shaft vibration were established. Finally, the theory of this paper was applied to the shaft vibration data analysis of Zhejiang Xianju pumped storage power station. The key characteristic indicators of vibration were extracted and the shafting stationary was evaluated. The results show that the established characteristic indicators have good performance in evaluating the stationary of shaft vibration, and have broad application prospects for the monitoring and performance evaluation of actual hydropower units.

Considering the lack of research on the ventilation characteristics of open flow spillway tunnels under high flow velocity conditions, based on a 50 m/s high-speed jet test device, this paper investigated the effects of flow velocity, ventilation tunnel area, and relative height of spillway tunnels on the ventilation volume and wind speed distribution in ventilation tunnels. By analyzing 44 sets of prototype observation data and 28 sets of experimental data, an empirical formula for calculating ventilation at high flow rates was proposed. The results show that the measured value of ventilation is 2.1-9.6 times of the standard value when the water flow velocity is 18.0-37.2 m/s. As the area of the ventilation tunnel increases, the rate of increase in ventilation volume gradually decreases, and the distribution of wind speed inside the ventilation tunnel is related to the area of the ventilation tunnel. The ventilation volume first increases and then decreases with the increase of the height of the spillway tunnel, and the change in the relative height of the spillway does not change the wind speed distribution characteristics. The calculated ventilation value by the improved formula is relatively close to the actual measurement value, with 3/4 of the data within the 20% error line range. Research results can provide guidance for engineering practice.

In view of the issue of the traditional questionnaire survey method with high human and time costs, a set of resettlement survey system based on B/S framework and cloud platform was designed on the basis of the analysis of the business needs of the survey of post resettlement support monitoring and evaluation of large and medium-sized reservoirs in Ningxia. The system implements the import, update, deletion of historical data, as well as the addition, modification, query, statistical analysis, and other functions of sample information through two subsystems: the household survey of mobile terminal and the data management of PC terminal, and was applied to survey work examples. Compared with the traditional survey method used before, the application results indicate that it has increased the average number of daily survey samples by about 1.5 times, saved 78% of the labor and time costs required for the collation and filing of survey data, and greatly reduced the repeated printing and output of paper survey forms, and to effectively avoided the less of paper data.

In order to study the distribution of the annular gap flow field during the bend start of the pipeline vehicle under different loading conditions. Numerical simulation combined with physical model test verification was used to study the annular gap flow field during the horizontal bend start of duct trucks with different loads. The results show that the increase of load does not change the overall distribution of the gap flow field velocity, but only changes the magnitude of the gap flow field velocity; Under different loading conditions, the axial flow velocity of the gap flow field of the pipe vehicle in the horizontal bend has the law of increasing and then decreasing from the inner wall of the pipe to the outer wall of the pipe vehicle. The circumferential flow velocity is more uniformly distributed at the section of the pipe vehicle gap inflow port and the section in the vehicle, but the opposite distribution of flow velocity on both sides of the sealing cover appears at the section of the gap flow outlet. The radial flow velocity is more uniformly distributed as far away from the support body and the seal cover, and the flow velocity increases significantly at the support body in the slit flow outlet section of the pipeline vehicle. This study explains the reasons for the formation of annular gap flow field distribution law and obtains the flow velocity distribution law of the gap flow field when the pipe vehicle is started at the bend with different loads. While improving and enriching the theory of annular gap flow, it provides theoretical basis for the application of hydraulic conveying in cartridge loading pipeline.

Based on the instability criterion proposed by the cusp catastrophe theory, the whole surrounding rock was judged, and the relevant tunnel excavation model was established by using the finite element software MIDAS GTS NX, and the changes in surrounding rock stress, displacement and maximum vibration velocity peak in the tunnel-fault system under the conditions of groundwater seepage and blasting were studied by taking No. 2 tunnel project of Daliangshan in Lexi Highway of Sichuan Province for an example. The results show that the comprehensive stiffness ratio of the surrounding rock k<1 and the bifurcation set equation Δ<0 are found by the calculation of the instability criterion, both of which indicate that the surrounding rock has the risk of instability. Under the seepage condition, the maximum principal stress of the fault surrounding rock is 27.71 MPa, and the displacement settlement of the vault is 307.83 mm. Compared with the non-fault area, the stress increases by about 20.64%, and the displacement increases by 105.21%. Influenced by blasting factors, the maximum vertical peak vibration velocity at the fault area is about 13 times that of the common surrounding rock, it is up to 162.97 cm/s. It can be seen that the existence of a fault will have an amplification effect on the dynamic response of surrounding rock. Both theoretical calculation and numerical simulation results show that the F3 fracture of the Daliangshan Tunnel has the risk of instability, and corresponding preventive measures should be taken in advance during construction.

Rock wall crane beam is a common bearing structure in underground powerhouse. Because it is directly supported on the surrounding rock, the stability of the rock crane beam is greatly affected by the geological conditions of the surrounding rock. Taking the rock wall crane beam of phase Ⅱ underground powerhouse of Fengning pumped storage power as an example, the distribution law of rock wall crane beam anchor stress and surrounding rock deformation were explained by analyzing the rock mass structural plane characteristics, the rock mass alteration effect as well as the in-situ observation data of the rock wall crane beam. Furthermore, the correlations between the bolt stress of the crane beam and the deformation of surrounding rock, the geological conditions as well as the construction process were deeply analyzed. The reasons for the large bolt stresses and the large deformations of surrounding rock of the crane beam were then explained, and the influence mechanism of rock mass structural plane and rock mass alteration on the stability of the crane beam was finally revealed. This research can provide technical support for the structural design, the construction organization and the safety demonstration of the rock wall crane beam, thus has practical engineering significance.

The scour of seawall toe is the one of the main factors for influencing structural stability of seawall estuary. The study of the scour characteristics at seawall toe under complex hydrodynamics and prediction method is of great significance for the seawall stability. Based on the field monthly measured topographic data since 2010, the time evolution of toe scour at Xijiangtang Seawall in Qiantang Estuary was discussed and the influence of flood was identified. The research results show that the seawall toe is eroded during flood, while there is silting during tide, and the critical flood discharge for scouring is about 5 000 m³/s. Based on the theory of sediment carrying capacity and riverbed deformation, a new scour prediction method is developed and the relative error is significantly improved within 20%.

The study of groundwater chemical varieties has a positive indicator effect on the regulation and improvement of regional groundwater quality caused by infiltration in the Yellow River Irrigation Area. The field in-situ infiltration test was carried out to monitor and analyze the recharge water-groundwater during the recharge process of paddy field and dry field, and the groundwater chemical evolution law was revealed by AquaChem hydrochemical analysis and SPSS mathematical statistics. Under the condition of infiltration, the characteristics of groundwater chemical change show four evolution processes: "rapid change and active zone in the early stage, gradual transition zone in the middle stage, gentle and stable zone in the late stage, and potential recovery zone after stopping irrigation". It can be seen from the experiment that the groundwater is mainly affected by the physical mixing of recharge water, accompanied by the water-rock physical adsorption ion exchange, chemical dissolution and leaching, etc. especially, the amount of recharge water in paddy field was large, and the water quality of recharge determined the direction of groundwater chemical evolution. At the same time, the concentrations of Na⁺、Cl^- of groundwater chemical components showed a good linear change, and the correlation coefficient was above 0.93, and the concentrations of Ca²⁺、Mg²⁺ showed a certain linear correlation with SO₄^2-、HCO₃^-. After stopping irrigation, the evaporation and concentration of groundwater was strong, and the ions of groundwater showed an increasing trend. Especially for Na⁺、Cl^-, the drainage and precipitation are timely needed after the irrigation. The research shows that the water supply of groundwater not only enriched groundwater sources, but also improved groundwater quality.

In order to understand the mechanism of crack formation in the RCC gravity dam body during operation, this paper takes the Shimantan reservoir dam as the research object, adopts a method of using the ESEL command in APDL language and the rotation of local coordinate system to complete the random aggregate delivery, and constructs a three-dimensional macro-micro finite element model of the No. 9 non-overflow dam section of the Shimantan dam. The simulation results of aggregate placement show that the method can quickly generate three-dimensional spherical and polyhedral aggregates, greatly improving the efficiency of aggregate generation. The results calculated by the macro-micro model are more consistent with the actual crack distribution of the dam, and the impact of the rapid rise in summer temperature and rapid drop in winter temperature on the cracking of concrete dams during operation cannot be ignored.

Concrete faced rockfill dam is widely used and rapidly developed in water conservancy and hydropower construction in China. This paper optimized the design method of concrete face dam based on BIM technology, realizing the dynamic comparison and selection of toe slab alignment by visual comparison and selection, achieving dynamic calculation of structural stress by structural parametric design and dynamic decision of dam excavation and filling through module-drawing-chart correlation measurement. As the result of dynamic design method, the model was applied to engineering digitization. Then the method was applied to the design of Gaopingqiao Reservoir face dam. Through the development of BIM plug-in, visual programming and customized intelligent cross section, it has played a role in improving the quality and efficiency of toe slab alignment, BIM-FEM joint analysis and zoning quantity calculation. In addition, the lightweight delivery of the model results supports the "intelligent application of Gaopingqiao digital reservoir" and gives full play to the value of the whole life cycle of BIM.