To explore the microseismic evolution characteristics of instability failure of surrounding rock of deep buried tunnel, biaxial compression tests of granite were carried out under different intermediate principal stresses (σ₂). The microseismic monitoring system and high-definition camera were used to monitor and record the failure of granite in real time. The evolution characteristics of microseismic b value and dominant frequency of rock failure process under different σ₂ conditions were analyzed, and the index of microseismic energy release (MSER) was proposed to describe the degree of rock failure. The results show that with the increase of σ₂, the cumulative microseismic energy release, the maximum value of lgN/b and the ratio of low frequency signal before rock failure, and the microseismic energy release rate at rock failure time all increase, while the minimum value of b value before rock failure decreases. In addition, the microseismic precursor of rock instability lists as follows: b value drops to less than 0.8; lgN/b rises to more than 3; High amplitude and low frequency signal appears. The precursors of rock slabbing are high amplitude low frequency signals accompanied by a small number of high amplitude high frequency signals, while the precursors of rockburst failure are that b value drops to less than 0.5, and lgN/b rises to more than 5, and high amplitude signal only appears in the low frequency band.

In order to obtain a more accurate calculation model of punching shear capacity of FRP reinforced two-way concrete slab, taking the FRP reinforced two-way concrete slab as the research object, using the research methods of literature review, data statistics, model analysis and regression calculation, and with the help of the commonly used calculation model of punching shear capacity of FRP reinforced two-way concrete slab, based on the collected punching test data of 98 FRP reinforced two-way concrete slabs, the inversion method of critical punching section coefficient of two-way slabs was used to establish a new calculation model of punching bearing capacity of FRP reinforced two-way concrete slabs. The model has high accuracy in predicting the punching bearing capacity of FRP reinforced concrete structures under concentrated load. The predicted results are in good agreement with the experimental database. The model has guiding significance for the design of punching shear capacity of FRP reinforced two-way concrete slab, which provides an important reference for further improving the accuracy of punching shear capacity calculation model of FRP reinforced two-way concrete slab in the future.

As a key point in early-warning of river system health, alert source verification is an important basis for eliminating hidden trouble and maintaining the river system health. Based on the analysis of the alarm source factors affecting the health status of Dongjiang river system, the alarm source index system was constructed, and the alert sources verification model of Dongjiang river system health was established by the partial least squares regression (PLSR) method. This model was used to verify main alarm source factors for affecting the health status of the Dongjiang river system (2015-2019), and the influence trend and degree of different alarm source factor on the health status of Dongjiang river system were analyzed. The results show that annual rainfall is the most direct and significant positive effect factor on the health status of Dongjiang River system. In addition, factors such as ecological water use, social development and river management level in this basin also play a promoting role. However, the flood disaster, sewage discharge, water for production and living, non-eco-friendly water conservancy facilities in this basin, and inter-basin water transfer have obvious negative effects on the health of Dongjiang river system.

The large pulses superimposed on the upper guide swing time-domain waveform measured by the eddy current displacement sensor of a generator-motor in a certain pumped storage station which affects the accuracy of the post-data processing. The data measured were analyzed in detail, and a three-dimensional finite element simulation model was established for calculation and verification. It is concluded that the fixed mode of the magnetic pole lead of the generator-motor on the upper end shaft is the main cause of large pulse. The temporary measures and completely improvement measures to ensure the accuracy of data were proposed, which are he pulse data elimination method and the sensor replacement method, respectively. It can provide the reference for the accurate measurement of the upper guide swing of a generator-motor with the same type of shaft-through mode.

The problem of waterlogging in old city has become the focus of natural disaster research. Taking Fenghuang District of Nanchang City as an example, the MIKE FLOOD model was established to analyze the risk and causes of waterlogging. Based on the above results, the SWMM model was used to conduct the research on LID layout and optimization. Analytic hierarchy process was used to evaluate its comprehensive benefits, and the optimal cost-benefit scheme was finally obtained. According to the study, the rainfall return period is 5 years, there are 16 waterlogging points, and the risk level of waterlogging in some areas has reached level Ⅳ. It can be seen that the urban waterlogging prevention and control research is urgent. LID combination facilities have a good effect on alleviating waterlogging. The scheme of 22.5% rainwater garden +7.5% pervious pavement is the best. This conclusion can provide technical reference for the following low impact development and construction of sponge cities and the proportion selection of facilities.

The space angles of inclined supporting arm of large radial gate are easily confused and mistaken, and its small errors may cause large structural errors, which will affect the manufacturing, installation and safe operation of the radial gate. Therefore, this paper defined, distinguished and calculated several key space angles of the radial gate inclined supporting arm. Taking an actual project radial gate as an example, the influence extent of each key angle of the inclined supporting arm on the manufacturing and installation accuracy of the gate was analyzed. Furthermore, this paper put forward several measures to improve the manufacturing and installation accuracy, which can be used as a reference for the subsequent design, manufacturing and installation of radial gate with inclined supporting arm.

The phenomenon of oil spilling and oil spilling in the lubricating oil system of the water guide bearing occurs frequently during the operation of the pumped-storage unit, which significantly affects the safety and stability of the unit and the operating environment of the power station. With the help of CFD numerical simulation technology and VOF multiphase flow simulation method, the dynamic characteristics of water guide bearing lubricating oil system in the multi-oil level working condition under the pumping mode of the pumped-storage unit were explored. The research results show that under the low oil level condition, the system flow cycle is formed faster, the flow state is stable and the oil level is low during the transition process, so the oil rejection phenomenon is milder, but too low oil level may lead to unfavorable control of oil temperature; Under the condition of high oil level, the phenomenon of oil spillage in the early stage of the flow mostly occurs near the side of the Pitot tube of the rotating oil basin, and it mostly occurs on the other side of the Pitot tube in the later stage of the flow. Compared with the traditional method of increasing the diameter of the Pitot tube, the method of optimizing the outer wall of the Pitot tube is more effective in suppressing the phenomenon of oil spillage. The results provide a theoretical basis for exploring the causes of the oil spill phenomenon in the water guide bearing lubricating oil system of the pumped-storage unit and the optimization of the oil slinger.

In order to analyze the dynamic response law of geotechnical slope, support and cavity structure under strong earthquake, taking a cavity section project in northwest China as an example, this paper firstly proposed a comprehensive management plan and then analyzed the management effect by combining field monitoring and FLAC^3D numerical simulation. Finally, the effect of support structure and cavern chamber on the dynamic response of rocky soil slope was analyzed under strong seismic load, and some suggestions for seismic protection of cavern section were discussed. The results show that after the treatment, the stability coefficient increases from 1.140 to 1.473, an increase of 29.2%; The imposition of the support structure effectively reduces the acceleration and displacement of the slope and cave roof axis; The presence of the cave chamber has a greater impact on the cave axis compared with the impact of the slope dynamic amplification effect; By analyzing the acceleration of the slope and the tunnel axis vault lining, the maddle is very important for the slope seismic resistance. It is suggested that the seismic protection length of the project should take the range of 3.4 and 4.8 times the diameter of the cave.

In order to analyze the influencing factors and their correlations of water use efficiency, incorporate all independent variables and overcome multicollinearity, the partial least squares method was used to study the correlation factors of water use efficiency in 2019 in China. The results show that the partial least square method can describe the correlation between variables effectively. Factors that are highly correlated with water consumption per ten thousand Yuan of GDP are natural conditions, social development level, GDP proportion of added value of primary industry, and the proportion of labor force in the water industry. The overall economic water use efficiency is high in the eastern region and low in the western region. Factors that are highly correlated with actual irrigation water consumption per mu of cultivated land are natural conditions and GDP proportion of added value of primary and secondary industries. Agricultural water use efficiency is high in the central region and low in the western region. Factors highly correlated with the water consumption per ten thousand Yuan of industrial added value are natural conditions, sewage treatment rate, urbanization rate and the capital proportion of water industry. Industrial water efficiency is high in the eastern region and low in the central region. Factors highly correlated with per capita public water consumption are per capita water resources, annual precipitation, sewage treatment rate, per capita GDP and GDP proportion of added value of primary and secondary industries. There is little correlation between regional factors and public water use efficiency. The research results can provide reference for the optimal management and rational utilization of water resources.

Aiming at the problem that the evaluation and prediction of water resources carrying capacity involves multi-factor comprehensive indicators, particle swarm optimization algorithm was used to optimize the training parameter penalty factor C and kernel parameter σ in the support vector machine model, and a water resources carrying capacity prediction model was established based on PSO-SVM. According to the index grade standard, the training set data was constructed to evaluate the water resources carrying capacity of Heilongjiang Province in 2017. The results show that the water resources carrying capacity index of Heilongjiang Province in 2017 is between 0.423 4 and 0.709 2. The water resources carrying capacity in some areas is at level II, the carrying capacity is weak, and there is still much room for improvement.