In order to study the response relationship between sediment discharge ratio (SDR) and influencing factors under actual water and sediment conditions, based on the measured water and sediment data of the Three Gorges Reservoir (TGR) from 2003 to 2018, this paper discussed the response relationship between SDR and various influencing factors on the basis of analyzing the characteristics of water and sediment from the reservoir, and established the formula of SDR in the main flood season. The results show that the correlation between SDR and single factor is not obvious, indicating that the SDR is affected by multiple factors. From the perspective of reservoir operation and regulation, the SDR is negatively related to the flood detention time, and the sediment discharge efficiency should be improved by shortening the flood detention time; From the perspective of incoming water and sediment, the greater the amount of sediment entering the reservoir, the greater the sediment discharge ratio of fine sediment is; Coarse sediment, on the contrary, is characterized by more coming and less discharging. In the main flood season, the relationship between the SDR and the proposed expression is good. This study can provide reference for the operation of TGR.

In the construction of hydropower projects under the same dam site, the height of water-retaining structures is a key index affected by many factors. In this paper, the responses of three design dam height schemes of a water-retaining structure under static and dynamic superposition conditions were analyzed. The results show that although the dead weight and reservoir water pressure of the arch dam increase with the increase of the dam height, the ground motion response of the arch dam does not all increase with the increase of the dam height. In this calculation case, the beam compressive stress and arch compressive stress on the upstream surface of the arch dam increase with the increase of the dam height, the beam compressive stress on the downstream surface decreases with the increase of the dam height, and the arch compressive stress first decreases and then increases with the increase of the dam height, the forward displacement and openness first increase and then decrease with the increase of the dam height. The research results can provide a reference for the design of water-retaining structures.

With many hydropower resources, Southwest China is a crucial area for current and future hydropower construction. However, most southwestern regions have deep overburden problems and high seismic intensity. The impact of these problems on the regular operation of high-face rockfill dams cannot be ignored. This paper established two-dimensional finite element models of 100 m, 200 m, and 300 m high-face rockfill dams on 100 m-deep overburden. Under the action of long-period ground motion and conventional ground motion, the elastic-plastic constitutive model was used to study the dynamic response characteristics of face rockfill dams with different heights on the same deep overburden. Compared with conventional ground motions, the results show that long-period ground motions significantly influence the acceleration of deep overburdened high-face rockfill dams. As the height of the dam body increases, the peak acceleration of the dynamic response of the dam body gradually decreases. Moreover, under the action of long-period ground motion, the higher the dam body is, the greater the displacement increment of the dam body in a short time. In this way, the resulting deformation is also more significant, which is not conducive to the seismic stability of the dam. Therefore, when building panel rockfill dams in areas with deep overburden and frequent long-period earthquakes, the effect of long-period ground shaking should be considered as a part of seismic stability evaluation.

A new anti-seepage structure between the asphalt concrete slab and geomembrane is proposed, which eliminates the concrete connecting plate and adopts backfilling elastomeric epoxy mortar into drilling holes. The mechanical and impervious properties, as well as anchoring parameters of the connecting joints in the anchorage area, are experimentally studied. It is found that the torsional and anti-pulling performance of the proposed anchoring approach is reliable. The suggested double-channel anchoring approach is more compatible with the large deformation of the geomembrane under a pressure of 0.4MPa. According to the results, optimal drilling parameters are proposed, which have the features of good porosity, reliable impermeability and less impact on the asphalt slab, providing a reference for engineering design.

The common deformation and failure mechanism of retaining wall at foot of earth-rock dam is mainly caused by insufficient bearing capacity of foundation, uneven settlement of foundation, temperature effect or insufficient anti-sliding stability. For a certain project, the retaining wall deformation characteristics are not consistent with the above causes after the drainage of the embankment foot of the earth-rock dam is changed to the retaining wall. The deformation is only visible at the expansion joints of the retaining wall, and the expansion joints are open, closed or misplaced. Through calculation and analysis, it is found that the expansion joint deformation is caused by the retaining wall horizontal displacement caused by the consolidation settlement of the dam, and the size of the deformation is related to the horizontal displacement difference between adjacent retaining walls. The larger the displacement difference is, the more serious the deformation is. At the same time, the horizontal displacement of retaining wall is related to the height of dam section, hydrogeologic conditions of dam foundation. Based on this, it is proposed that after the prism drainage of the downstream earth-rock dam is changed into gravity retaining wall, in addition to the design and calculation according to the standard requirements, the horizontal displacement difference between retaining walls should also be calculated, and the damage of retaining wall displacement and poor drainage to the downstream drainage system of the dam body should be considered. The research results have a good reference value for the correct analysis of deformation mechanism and anti-slip design of retaining wall at dam foot.

Affected by global climate change and human activities, extreme weather events such as drought and rainfall have led to landslides and other disasters in the reservoir dam. At the same time, the impact of evaporation and rainfall on the seepage and stability of the dam slope has not been considered in the design specifications for roller compacted earth-rockfill dams. Taking an earth-rockfill dam as the research object, a finite element calculation model was established to study the impacts of evaporation, rainfall and reservoir water level changes on the pore water pressure, saturation line and safety factor of anti-sliding stability of the earth-rockfill dam. And the cause mechanism of landslide was analyzed in combination with geological exploration and monitoring data. The results show that evaporation and rainfall have a great impact on the pore water pressure of the soil within 0~2 m of the downstream dam slope. The difference between the measured water level of the piezometer and the saturation line calculated by the finite element method is less than 0.4 m. At the initial stage, evaporation improves the stability of the dam slope, but evaporation causes the surface fill of the dam body to shrink and crack continuously, providing a channel for rainfall infiltration. With the increase of the number of rainfall and evaporation cycles and the rising of the reservoir water level, the cracks continue to increase, and the local stagnant areas near the bottom of the cracks are interconnected to form a saturation zone, which leads to the instability and damage of the shallow dam slope downstream of the dam. The research results provide a scientific basis for improving the design specifications of earth-rockfill dams and the early warning of reservoir dam landslides.

The measured deformation data contain rich temporal and spatial information and evolution laws of dam deformation. To study the co-integration relationship of the aging deformation of extra-high arch dams, wavelet decomposition was firstly used to obtain the aging component of the dam displacement. Considering the weak spatial integrity of extra-high arch dams, the FCM clustering algorithm was utilized to realize the regionalization of aging deformation. With the help of the idea of regional linearization, the spatial nonlinear co-integration relationship of the whole dam aging deformation was transformed into several approximate linear co-integration relationships within different regions. The zonal co-integration model was established to describe the development law of time-varying co-integration in different regions of the dam. The co-integration development monitoring and early warning of multi-measuring points aging deformation were realized by co-integration residual.

The Wangyu River is an important watercourse connecting the Yangtze River and Taihu Lake. Relevant hydrological data shows that the pumping opportunity can account for 25.9% of the total drainage period from the Wangyu River to the Yangtze River, which indicates that the pumping station plays a crucial role in the drainage period of Taihu Basin. The current design lift (2.5 m) of the pumping station is higher than the actual operating lift, and the running time of the pumping station exceeding 20% of the installed designed capacity accounts for 65.9% of the total operation time. According to the design specifications of the pumping station and relevant local standards, combined with the analysis of the hydrological data, it is recommended to adjust the design lift of the pump station to 1.78 m in the subsequent upgrading of the pumping station. The optimized design lift is more compatible with the actual operating environment of the pumping station, and it also reduces the operating costs of the pumping station such as power consumption, and prolongs the service life of equipment, which is of great significance for the overall benefits of the Wangyu River Hydro-junction.

At present, most leakage location methods rely on the hydraulic model of the pipe network. However, when the accuracy of the hydraulic model cannot meet certain requirements, or when the model cannot be established due to the lack of basic data, the model-based method will fail. For this purpose, the study of the leakage location of the water supply network was carried out on the basis of pressure monitoring data. Based on the modeling theory of graph theory, the interpolation method for estimating the node pressure of pipe network was obtained. The leakage position was estimated by analyzing the residual of the pressure monitoring value of each node and the measured value after the leakage occurs. With the help of Bayesian theorem, time-series reasoning was carried out on the positioning results, and the node with the largest probability in a certain period of time was regarded as the location where leakage occurs. By using the case of L Town, the state of pipe network was simulated when single point leakage occured, and the feasibility and location performance of the leakage location method were verified.

When the source-based reduction facilities cannot be carried out during the construction of sponge city, the stormwater control measures (SCM) are usually set up at the terminal drainage outlets to achieve the goal of runoff control and pollutant reduction. Because there is usually large drop between the drainage outlet and the waterfront zone in mountain city, resulting in a high flow rate of water from the drainage outlets, it is easy to cause strong hydraulic erosion to the SCM and may adversely affect their normal operation. Based on the falling-sill dissipation facility installed according to the high drop topographic features of drainage outlets in Chongqing urban, the numerical model with FULENT software was constructed to simulate the hydraulic process of different energy dissipation configurations in this study. The results show that the solid-baffle typed falling-sill dissipation facility has out-performance energy dissipation, and the energy dissipation rate was as high as 90%, and the outlet velocity of the end of facilities was irrelevant to the inlet flow, while only related to single drop height. The higher the single drop height, the water flow was susceptible to form a hydraulic vortex in the backwater area of falling-sill under the influence of potential energy, which can lead the greatest extent of turbulence kinetic energy dissipation, and finally result in a gradual decrease of the maximum pressure of water flow in the horizontal direction to achieve the targeted hydraulic energy dissipation.