For Guxian hydro-junction project, concrete volume is huge, and the construction period is tight, construction technology and parallel planning are key problems in the construction of high RCC gravity dam. Therefore, the simulation technology of discrete event system was introduced to establish the construction simulation model in line with the dam type characteristics of the dam to simulate and calculate the construction process of concrete partition, parallel and jump warehouse. After multi-scheme simulation, the flat inclined layer technology and the corresponding warehouse surface partition scheme were recommended, and the warehouse surface control criteria were put forward. It provides all-round data support for Guxian project, and its simulation model can be used as a reference for other similar projects.

Aiming at the problem of power system structure vulnerability, the advantage of multi-index evaluation can be combined with Pajek tool to identify the key nodes of power grid. First of all, based on the complex network theory, considering the power network topology characteristics, structural vulnerability evaluation index system of integrated power system was established. Secondly, in terms of evaluation methods, fuzzy comprehensive evaluation method and CRITIC method were used to calculate the subjective and objective weights of each evaluation index. Finally, combination weighting VIKOR was proposed to calculate the weight value of each node and obtain the ranking result of importance. Taking IEEE-118 system as an example and comparing with different evaluation methods, the results show that this method is feasible.

Focusing on the influence of the project of water diversion from Yangtze River to Taihu Lake on the hydrodynamic characteristics of Gonghu Bay, the physical model of the wind-driven currents in Taihu Lake was used to analyze the influence on the hydrodynamic characteristics and the vertical flow velocity and planar circulation distribution in Gonghu Bay under the different wind speeds and different diversion flow of Wangyu River in the typical wind field in summer. The results indicate that the variation of Wangyu River diversion flow affects the hydrodynamic characteristics of Gonghu Bay mainly in the near and middle regions, but has little impact on Taihu Lake; The implementation of the water diversion project from Yangtze River to Taihu Lake significantly changes the vertical velocity distribution characteristics on the outlet axis of Wangyu River in the near and middle regions, but has no effect on the vertical velocity distribution characteristics at the junction section; The characteristics of the planar circulation in Gonghu Bay are affected by both wind speed and diversion flow, the changes of wind speed and diversion flow have a significant impact on the area, location and shape of the plane circulation. The research results can provide hydrodynamic theoretical support for evaluating the impact of the water diversion project from Yangtze River to Taihu Lake on the water environment of Gonghu Bay.

Aiming at the collapse and failure of high dangerous rock in Zhaojiaya, Xingshan County, numerical simulation methods were used to simulate the stability, evolution law and movement characteristics of the regional dangerous rock mass, so as to obtain the movement track, bounce height and impact energy of the collapsed rock. The results show that the Zhaojiaya dangerous rock has good stability under natural conditions. Under continuous rainfall or rainstorm, the fissure water gradually permeates, and there is the possibility of collapse and failure of the main control structural plane. After the collapse and destruction of the dangerous rock, most of the fallen rock will stay on the slope, and a few of the fallen rock will stop on the road at the foot of the slope after the collision and rebound. Combined with the actual situation of the site and RocFall simulation, the governance measures of "danger clearing + slope leveling + passive protection net" were proposed. The research results can provide reference for similar disaster control projects of high dangerous rock collapse.

In order to solve the problem of “seeing the sea in rainy season and having no water to use in drought” in cities in desert areas, taking Kuwait as an example, based on the concept of sponge city in conventional areas, combined with the actual climatic and geological conditions in desert area, the permeability coefficient of 5-50 m underground layer was calculated according to the experimental data obtained from the soil permeability test in N5-1 region. A number of seepage analysis schemes of rainwater storage tank were established, and different schemes were modeled and calculated. The results show that the combination of filling high permeability material around the rainwater storage tank and adding vertical recharge well at the bottom can solve the problem that rainwater cannot penetrate into the underground aquifer effectively.

In order to further analyze the permeability characteristics of cohesionless soil containing carbonate sand, South China Sea carbonate sand and fine grain quartz powder were used as test materials to prepare test soil samples. The GDS high-pressure triaxial apparatus test system and constant head permeameter were used to carry out research on the influence of carbonate sand content, initial void ratio and effective stress on the permeability characteristics of cohesionless soil. And then an empirical model of permeability coefficient considering effective stress was established. The test results show that when the content of carbonate sand is less than 40%, the grain structure is cohesionless soil matrix, and the pore structure is determined by fine grained soil; The structure of carbonate sand sample is the skeleton structure of sand particles, and the magnitude of permeability coefficient increases significantly; With the increase of effective stress, the permeability coefficient of the sample decreases significantly. An empirical model for the permeability coefficient of cohesionless soil with carbonate sand was established. The model parameters were closely related to the properties of the soil sample. The calculated values were in good agreement with the test values. The research results can provide reference for practical projects.

The existence of fissures seriously affects the stability performance of rock structures, and how to reasonably describe the characteristic change law of nonlinear mechanics of rocks containing fissures has been an important research point in recent years. Based on this background, a smooth particle dynamics numerical simulation method (RSMPM) is proposed considering material point failure. The RSMPM was based on the basic calculation principle of the MPM algorithm, the Mohr-Coulomb damage criterion was adopted to traverse all material points in each calculation step, and the failure process was carried out for the material points that reach the damage condition. The dynamic fracture process of the rock was described by the failure process of the material points. The accuracy of the proposed numerical simulation method was verified by comparing the numerical simulation results (crack extension process, main stress cloud distribution) of single crack standard cube specimens and single crack Brazilian disc specimens with previous research results. The research results provide a certain reference for the application of smooth particle dynamics methods in rock mechanics engineering and the understanding of rock fracture mechanisms.

In order to investigate the non-stationary characteristics of runoff series in changing environments and to better predict the occurrence of flood events, taking Hutuo River in the Haihe River Basin as the research object, GAMLSS model was used to conduct a non-coherent frequency analysis of the runoff series during 1970 and 2012 by taking time, reservoir indicators and climate indicators as covariates. The results show that the runoff series of Hutuo River has obvious non-stationary characteristics with trend and abrupt changes. The GAMLSS model can better simulate the runoff series in changing environments and describe the flood regimes under the influence of climate change, thus outperforming the traditional model. Changes of the large-scale climate indicators NINO1+2 and NAO significantly affect the flood events in the Hutuo River, with increasing values of these two climate indicators indicating low flood risk and decreasing values indicating high flood risk.

In order to improve the accuracy of real-time flood forecasting in Jinhua River basin, the basin flood forecasting model coupled with Mike 11 Nam and Mike 11 HD and the real-time correction model based on Ensemble Kalman filter were established, and the real-time correction of flood forecasting in Jinhua River basin was realized. The simulation effect of the basin flood forecasting model on the main stations in the basin is good, and the simulation accuracy of flood discharge and flood level is high. When the real-time correction model is within 10h of the forecast period, the correction effect decreases with the increase of the forecast period, and the prediction error can be effectively reduced in the early stage of the forecast period. On the whole, the established basin flood forecasting model and the real-time correction model based on Ensemble Kalman filter can meet the application requirements of flood forecasting in Jinhua River basin.

In the process of the rise and fall of the reservoir water level in the dry-hot valley reservoir area, the dry and hot conditions in dry and hot valley where the surface rock mass is located need to be considered, that is, the heat and wet cycle. Based on this, repeated shear tests of joint rock sample under heat and wet cycling were carried out. The results show that with the advance of the test period, the shear stress-shear displacement curve decreases as a whole, and the shear strength of the joint surface deteriorates obviously; The deterioration effect of shear strength under repeated shearing is particularly significant only in the initial state after the shear strength is modified; The deterioration effect of shear strength under heat and wet cycle is mainly concentrated in the first five cycles; After modification, the shear strength, cohesion and internal friction angle of the joint surface show a deterioration trend of “first fast and then slow” only under heat and wet cycle, which is consistent with the experimental results. The research results have guiding significance to the deterioration of rock mass and the stability analysis of bank slope in water-level-fluctuation zone of dry-hot valley.