Temperature is one of the main loads of super-high arch dams. (1) Background: a super-high arch dam in southwest China was taken as an example in this paper and the temporal-spatial evolution law of dam temperature was analyzed based on the monitoring data. (2) Methods: the finite element simulation analysis method was adopted to invert the boundary conditions of temperature on the upstream surface and the thermal parameters of the concrete, and the temperature evolution process of the arch dam in long-term operation was simulated and analyzed. After the distribution characteristics of the designed reservoir water temperature and the actual reservoir water temperature were compared, the difference in the temperature field of the arch dam during the impoundment and operation under the designed and actual conditions was studied. (3) Results: the temporal-spatial evolution law of the temperature in the dam operation period accords with the conventional knowledge, and the calculated value through simulation feedback is in good agreement with the monitoring value, which can reflect the actual temperature field distribution of the dam. (4) Conclusions: under the design condition, the dam temperature rose slowly after closure grouting and then tended to be stable. Under the actual condition, the temperature rose by 7.1~9.2 °C after closure grouting, reached the highest temperature in about 8~12 years, and fell back to a stable temperature in 40~80 years.

Difficulty in clarifying the deformation characteristics of deep rocks under a high water pressure environment is a technical bottleneck restricting the safe operation of large hydropower stations. In order to study the effect of reservoir water level changes on the mechanical behavior of deep limestone, a series of mechanical tests were conducted under different dynamic high water pressure environments using a self-developed hydraulic loading test device. The test results show that the unsaturated limestone always undergoes compressive deformation during the linear increase in external water pressure, and the saturated limestone changes its deformation state from compression to expansion during the linear decrease in external water pressure. The stress–strain curve of limestone shows apparent hysteresis characteristics during the cyclic increase and decrease in external water pressure. Overall, the rock strain rate showed a significant negative correlation with the external water pressure, and the rock deformation modulus showed a certain positive correlation with the external water pressure. During hydraulic loading, saturated rocks had a smaller range of variation in the strain rate and deformation modulus and were more resistant to deformation than unsaturated rocks. Limestone was subjected to both external water pressure and internal pore water pressure in a cyclic cycle, where pore water pressure promotes pore creation and expansion, while external water pressure prevents water from degrading the pore structure. The periodic change of water pressure has a significant influence on rock mechanics and deformation behavior, and the rock mass will undergo elastic deformation, plastic deformation, and even fracture. Further study of this deformation rule can provide a more accurate theoretical basis for the safe operation of water conservancy projects.

In the anti-seismic analysis of concrete high dams, only the damage cracking of the dam concrete is usually considered, and the nonlinear characteristics of the dam foundation rock during the earthquake are not considered. Taking the Koyna gravity dam in India and Shapai arch dam in China as examples, this paper adopts the nonlinear time-history analysis method and takes into account the comprehensive influence of the radiation damping of infinite foundation, the hydrodynamic interaction between dam and reservoir, the nonlinear dynamic contact between various joints in the dam body and foundation, and the damage of dam concrete and foundation rock mass in the damage evolution process, analyzes damage evolution process of dam body-foundation system under earthquake action and the influence of foundation rock mass damage on seismic failure mode of concrete dam-foundation system, and compares the numerical simulation results with the actual earthquake situation. The calculation results show that after considering the damage of the dam foundation rock mass, the rock mass of the dam heel firstly appears to be damaged under the action of the earthquake and gradually expands into the interior of the foundation. The dam heel and the foundation surface are not damaged. The numerical simulation results are more in line with the actual situation of earthquake.

Cemented granular materials (CGMs) represent a transitional class of geomaterials where mechanical behavior is governed by the interplay between a discrete granular skeleton and a continuous cementitious matrix. While previous studies have focused on idealized spherical particles, this study aims to quantify the influence of the cement filling ratio (ranging from 10% to 100%) on the mechanical constitutive behavior of CGMs fabricated with large, irregular granitic aggregates (14–20 mm). Unconfined compressive tests and splitting tensile tests were conducted to evaluate the evolution of strength, stiffness, and failure modes. The results reveal a distinct mechanical transition governed by the cement filling ratio (${\rho }_m$). The elastic modulus and splitting tensile strength exhibited a linear increase with ${\rho }_m$ (R2 > 0.95), indicating a direct dependence on the volume fraction of the binding phase. In contrast, the unconfined compressive strength (UCS) and peak strain displayed a bilinear growth pattern with a critical inflection point at ${\rho }_m$ = 80%. For the specific irregular granitic aggregate skeleton investigated, this threshold marks the transition from contact-dominated stability to matrix-dominated continuum behavior. Below this threshold, strength gain is limited by the stability of discrete particle contacts; above 80%, the material behaves as a continuum, with UCS increasing rapidly to a maximum of 41.78 MPa at 100% filling. Furthermore, the dispersion of stress–strain responses significantly decreased as ${\rho }_m$ exceeded 50%, attributed to the homogenization of stress distribution within the specimen. These findings provide a quantitative basis for optimizing cement usage in ground reinforcement applications, identifying 80% as a critical design threshold.

Concrete stress is a key factor influencing the operational safety of concrete dams, and understanding the true distribution and variation of stress is a major research focus in the field of dam engineering. In the heel region of the dam, internal voids in the concrete may allow external water infiltration under high hydraulic head, leading to changes in the concrete’s elastic modulus and Biot coefficient. These changes, in turn, affect the effective stress experienced by the concrete. Consequently, the measured stress in the heel and toe regions may differ from conventional understanding and standard calculation methods for dam stresses. This is particularly evident in the following aspects: after water impoundment, compressive stress in the dam heel is higher than in the dam toe, with the heel stress exceeding the calculated value by a significant margin, and the variation in stress during the impoundment process being smaller than the calculated value. To address these issues, this paper proposes a theoretical method for measuring the Biot coefficient of concrete through experimental testing and innovatively develops the corresponding experimental equipment. This equipment can accurately simulate the conditions of the dam under different water depths (confining pressures) and measure the deformation of concrete caused by changes in water depth. Based on this equipment, tests were conducted on the elastic modulus and Biot coefficient of dry and saturated concrete specimens under different confining pressures. The Voigt–Reuss–Hill mixed average modulus formula was applied to calculate the elastic modulus of the concrete matrix, exploring the influence of pore water on the mechanical properties of the concrete. The results indicate that the pore water inside the concrete increases its equivalent elastic modulus during the testing process. In numerical simulations of the dam, this increased modulus due to pore water is often overlooked, leading to an underestimation of the results. This partially explains why the measured compressive stress in the dam heel consistently exceeds the calculated values. According to the Biot coefficient calculation theory proposed in this paper, the Biot coefficient of concrete varies with its water content. The Biot coefficient is lower in specimens with high water content compared to those with low water content. Using the Voigt–Reuss–Hill mixed average modulus formula, the elastic modulus of the concrete matrix obtained from the tests was found to be 28 $\mathrm{G}\mathrm{P}\mathrm{a}$, which is in good agreement with the results from regression analysis. These findings are of significant importance for the safe operation of concrete dam engineering.

This study deeply explores the permeation deformation mechanism of limestone cores in deep-water environments. Through a customized test device, the mechanical responses of deep-water rocks under different moisture content conditions are simulated. The device is composed of a pressurization system, a pressure vessel, and a data acquisition system, which can accurately apply high water pressure and monitor the stress and strain changes in the core in real time. The cores used in the experiment were cut to standardized sizes and subjected to strict saturation and drying treatments to ensure the consistency of test conditions and the accuracy of data. The mechanical behaviors of cores under four working conditions of dryness, 50% moisture content, and 100% moisture content are analyzed. Through the cyclic process of pressurization and depressurization, the changes in the strain characteristics of the cores are observed. The research results show that when pressure is applied for the first time, low moisture content cores will absorb water and expand, and the strain will increase and then tend to be stable as the pressure increases. There is no such process for cores with 100% moisture content. Water pressure is positively correlated with the elastic modulus of rocks, negatively correlated with the strain rate during pressurization, and positively correlated during depressurization. Moreover, an increase in moisture content reduces the average strain mutation, reduces the average strain rate amplitude, and increases the elastic modulus. This study provides important theoretical support for the design and construction of deep-water rock engineering and provides a reference for further research in related fields.