In order to alleviate the water shortage in the development of oil and gas resources, horizontal wells are often used to exploit groundwater resources, but there is little analysis on the factors affecting the water intake of horizontal wells. Therefore, the numerical model is used to simulate the horizontal well mining mode and explore the influence of horizontal well layout direction, burial depth, pipe length and well pipe permeability on the water intake effect. The results show that considering the water intake efficiency and construction difficulty, the optimal horizontal well layout direction should be laid along the incoming water direction, and the location should be located in the upper layer of Luohe Formation as far as possible. The recommended pipe length and well pipe permeability are 800 m-1 000 m and 0.15, respectively, and the corresponding production volume is 1 368 m³/d-2 389 m³/d. The research results have important guiding significance for alleviating the shortage of water resources in the development of oil and gas resources in the eastern region of Longdong and formulating reasonable development strategies of water resources.

Fenghuangjing new station belongs to the front inflow pump station with large diffusion angle. Large scale off-wall reflux is easy to occur at the bank walls on both sides of the forebay, which can not provide good inlet conditions and endanger the safe and stable operation of the pump station. Forebay at river diversion side of Fenghuangjing new station was taken as the research object. Based on the CFD numerical simulation software, the improvement effect of trapezoidal sill position and height on the flow pattern in the forebay of the front inflow pump station with large diffusion angle was studied. And the numerical simulation results were verified by physical model tests. The results show that when the trapezoidal sill is located at 10 m from the entrance of the forebay and the height of the sill is 1.2 m, the inflow conditions of Fenghuangjing new station can be better improved. The research results can provide technical support and reference for this project and the similar projects.

In order to solve the problem of instability of the bottom plate and pressure damage of the suspended grid due to the excessive time-average pressure in the suspended grid stilling basin, numerical simulation was used to study the water level difference and pressure field in four different arrangements of the suspended grille under the design and calibration flow. Two optimization schemes of the combined toe pier-suspended grille and circularized suspended grille were proposed on the basis of the scheme 4 with better water stabilization effect. The results show that the combined toe pier-hanging grille optimisation scheme can reduce the time-average pressure at the bottom plate by 63% and 50% compared to scheme 4 at the design and calibration flow rates, effectively reducing the difference in the time-average pressure Δp₂ between the upper surface C and the lower surface D of the grille in the basin. The rounded grille optimisation scheme can make the total pressure distribution at the grille more uniform and avoid local damage to the grille. Therefore, it is recommended to choose a combined auxiliary energy dissipation method of toe pier-suspended grille for high flow stilling basin with pressure requirements.

In order to solve the upstream demand of small fish with weak swimming ability in the vertical slot fishway, an anti-flow cylinder is added to the migration channel between the long and short baffles. Hydro 3D open source code and LES-based numerical simulation technology are used to simulate the flow field in the vertical slot fishway before and after the anti-flow cylinder is added. According to the streamline distribution in the time-averaged flow field, the results show that the area of the vortex area in the pool is reduced after adding the blocking cylinder, which solves the problem of lack of sense of direction in the process of fish upstream in the traditional vertical slot fishway. The turbulent kinetic energy in the pool increases by 20%, which raised the energy dissipation of the water flow and reduced the energy consumption during the fish upstream process. The increase of vorticity around the long and short baffles and the blocking cylinder may have an adverse effect on the stability of the fish during swimming. However, according to the vortex structure, the vortex diameter behind the blocking cylinder is less than 76% of the body length of the small fish, so it has little impact on the stability of the fish during swimming. In summary, the setting of a flow blocking cylinder in the vertical slit fishway can improve the success rate of small fish upstream.

River bank collapse is very common in natural rivers and plays an important role in the evolution of river channels. In order to quantitatively study the influence of river bank soil properties and bank slope inclination on river bank stability, the BSTEM model for calculating river bank stability and bank toe erosion was adopted, and six typical river bank materials were selected to study the stability of homogeneous river banks under six bank slope inclination angles. Under the condition of ignoring the water table, the collapse modes of non-cohesive bank slope and cohesive bank slope are different. For non-cohesive bank, the dominant factor affecting bank stability is the effective internal friction angle. The larger the effective internal friction angle is, the more stable the bank is. For cohesive bank, the dominant factor affecting the stability of the cohesive bank is effective cohesion. The greater the effective cohesion is, the more stable the bank is. When the effective cohesion difference is the same, the smaller the absolute value of the effective internal friction angle difference is, the more the safety factor increases. The increase of bank slope inclination reduces river bank stability and the safety factor. The larger the effective internal friction angle of the non-cohesive bank is, the more sensitive the safety factor to the change of bank slope inclination is. For cohesive banks, the greater the effective cohesion is, the more sensitive the safety factor to the change of bank slope inclination is.

Water and sediment conditions are complicated in waters affected by the interaction of flood and tide. Therefore, the bend regulation in these waters is more difficult and its effect is more uncertain than that of ordinary rivers. This paper aims at the above problems by taking the treatment project of Wenjiayan bend as an example, which lies in Qiantang estuary. This treatment project consisted of the riprap protection at concave bank and retreating dike at the opposite bank combine with the shoal-cutting measure. Based on the observed hydrology and topography data for years, the variation of flow conditions, deep channel distribution, scouring elevation and siltation velocity before and after the project was analyzed. The results show that the bend effect is greatly weakened and flow conditions are improved after the treatment. Meanwhile, the deep channel in the bend reach moves from the foot of the dike to middle. These results can provide reference for measures to similar sharp-bend treatment. Meanwhile, the balance section area after the project implementation was predicted through the methods of river correlation coefficient method and section average statistics. The dredging conditions of the reach were determined, which can provide guidance to operation and maintenance for the subsequent project.

The flow field characteristics of vortex setting chamber (VSC) play a decisive role in its water and sediment separation performance. In order to clarify the influence of the inclination angle of the curved deflector on the flow field characteristics of VSC, the large eddy simulation and VOF method are used to study the three-dimensional flow field characteristics of the VSC when the inclination angles of the curved deflector are 5°, 10° and 15° respectively, and the flow field characteristics of the VSC with the plane deflector under the same inlet flow rate are compared. The results show that the use of curved cantilever deflector will increase the eddy current intensity in the VSC chamber and reduce the range of low velocity zone. The increase of the inclination angle can improve the stability of the air vortex, increase the strength and size of the air vortex, which is beneficial to the separation of water and sediment. The radial velocity in the cone area increases with the increase of the inclination angle, and basically points to the center of the VSC, which is conducive to the rapid transport of sediment to the bottom hole of the sediment discharge. The velocity of the overflow flow on the surface of the curved deflector is greater than that on the surface of the plane deflector, and the flow velocity on the deflector is the largest when the inclination angle is 15°.

There are some problems in construction, such as inaccurate material parameters and unclear influence of shield operation parameters on ground settlement. Based on a water-rich sand layer shield construction diversion tunnel, an orthogonal experiment is designed by setting the index of ground surface settlement, and a three-dimensional numerical simulation is used to analyze sensitivity of different material’s parameter. Mechanical parameters of materials are inverted according to the observed settlement. The subsidence lines under different excavation pressures, different synchronous grouting pressures and different speeds of the shield are calculated. The result shows that the surface subsidence is most sensitive to the change of internal friction angle of sand layer. Increasing the internal friction angle of the sand layer and the elastic modulus of the lining will reduce the settlement. The speed of the shield has a great influence on the subsidence. Increasing the speed of the shield, the maximum settlement of the surface settlement curve will increase, and the width of the "settlement tank" will also increase. The maximum settlement and the width of "settlement tank" decrease with the increase of excavation chamber pressure or synchronous grouting pressure.

In view of the lack of research on the creep characteristics of hydraulic concrete in water from mesoscale scale, a meso-finite element model of concrete specimen of "aggregate-mortar-transition layer" was established. Based on the test data of tensile and compressive creep in water, the method of "orthogonal design-neural network-meso-finite element calculation" was adopted to implement the inversion analysis of the tensile and compressive specific creep of hydraulic concrete specimens at mesoscale. Finally, the relationship between tensile and compressive specific creep of hydraulic concrete and mortar was compared. The results show that the variation law of tension creep degree of hydraulic concrete in water is similar to that in sealed. The creep degree of mortar water is 2.4 times of hydraulic concrete water under conditions of tensile and compressive creep.

In order to understand the influence of thermodynamic coupling factors on the damage characteristics of hydraulic engineering concrete materials within 100 ℃, the temperature of concrete specimens is applied and stabilized by self-designed temperature control device, and non-destructive monitoring acoustic emission technology (AE) is used to monitor the uniaxial compression of concrete under different temperature environments. The AE ringing count and amplitude change during concrete failure at five different temperatures are explored, and the constitutive model of concrete damage under thermodynamic coupling is established according to the relationship between ringing count and stress. The results of the cumulative ringing count and amplitude show that the higher the temperature, the higher the number of damage events, the more severe the degree of damage, respectively, the cumulative ringing count increases by 5.25 times at 100 °C compared with 20 °C, and the amplitude can be increased by 20-40 dB in the late loading stage compared with the previous stage. The established damage constitutive model shows that the increase of temperature will increase the degree of damage of concrete, which provides a theoretical reference for understanding the influence of thermodynamic coupling on the damage of concrete materials.