No abstract

An accurate groundwater‐surface water (GW‐SW) and heat coupling model (WHCM) aids in exploration of water migration and heat transport laws in the sedimentary layers of riverbeds and riparian zones, which is critical for understanding the transport patterns of contaminants in sediments. In this paper, a novel WHCM for GW‐SW interaction is proposed by incorporating an effective soil thermal conductive model (ESTCM) into the advection‐dispersion equation to address the shortcomings of current simulations that fail to account for the nonuniform heat transfer of soil. The model is developed in COMSOL, and the numerical implementation method is illustrated in detail. Furthermore, six recommended ESTCMs are examined in the WHCM to validate and compare the model simulation effects based on field test observations in the Walker River, USA. The results demonstrate that the proposed model performs better than the model that does not account for the nonuniform heat transfer effects of the soil in simulating GW‐SW water and heat exchange. Meanwhile, the proposed model's simulation effects based on the Y2019 model perform the best. The orthogonal test revealed that the hydraulic conductivity ks and porosity n are the two most sensitive parameters influencing the model output results of groundwater seepage velocity and temperature, respectively. The efforts of this work can offer technical assistance and a guide for enhancing the simulation effect of river GW‐SW water and heat exchange.

The deformation of dams has always been the focus of dam safety research. To more accurately study the effect of the Duncan–Chang model on the deformation of homogeneous Earth dams, this paper simulates the displacement variation of a homogeneous Earth dam through the finite element method based on the Duncan–Chang E-B model. The sensitivity of the Duncan–Chang E-B model parameters and the dam material density on the displacement of a homogeneous earthen dam in Gansu Province, China, were investigated using single-factor and multifactor analysis methods. The results show that the displacement variation of the dam during the completion and operation periods is consistent with the general rule for Earth and rock dams; the three parameters R f , φ 0 , and Δ φ are more sensitive to dam deformation; and the three parameters m , n , and K are less sensitive to dam deformation.

Pumped storage power station (PSPS) is an important clean energy project that plays an important role in ensuring the economical, safe, and stable operation of power systems and alleviating the contradiction of peak load regulation. Deformation analysis of the built and under construction PSPS dam was an important process of dam design and operation, which was of great significance to ensure the safe operation of hydraulic structures in the reservoir site. Nevertheless, there were many parameters involved in the model for analyzing dam deformation, which brings a large workload to the inversion and application of model parameters. In this study, the asphalt concrete face rockfill dam (ACFRD) of a PSPS in Ningxia, China, was taken as an example, a dam deformation 3D finite element analysis model based on the Duncan–Chang E-B model was constructed, and the orthogonal test method was used. The model parameters of the main rockfill zone, secondary rockfill zone, and reservoir bottom backfill zone were taken as factors for the sensitivity analysis of horizontal displacement of dam H, vertical displacement u, and asphalt concrete face tensile strain ε. The results showed that initial bulk modulus base Kb, damage ratio Rf, and initial elastic modulus base K had a relatively higher sensitivity and had significant impacts on the calculation results, while internal friction angle φ, fraction angle reduction φ, bulk modulus index m, and elastic modulus index n had a relatively lower sensitivity, which had no significant impact on the calculation results. Therefore, when using the Duncan–Chang E-B model to analyze the deformations of a PSPS dam and asphalt concrete face, Kb, Rf, and K should be the focus. Parameters with a low sensitivity could be determined by engineering analogy so as to achieve the purpose of improving calculation efficiency under the premise of ensuring calculation accuracy. Meanwhile, these parameters should also be strictly controlled during construction. The results of this study could provide a reference for the design and safety assessment of ACFRD in PSPS.