Dam Materials Research Articles

Analysis on dynamic characteristics of dam material and seismic response of embankment dam in Longyang Reservoir

PurposeThe geological conditions of Longyang Reservoir are complex and it is located in strong earthquake area. In order to determine its seismic characteristics, the seismic response and residual deformation of embankment dam should be studied to provide calculation basis for dam design and construction.Design/methodology/approachBased on the geological survey data of Longyang Reservoir, the dam filling materials are tested by dynamic deformation tests, and the equivalent linear constitutive model parameters of the filling materials are obtained. Based on Duncan-Chang E-B model, the stress state of embankment dam in Longyang Reservoir before earthquake is calculated, and the dynamic response and earthquake residual deformation of embankment dam in Longyang Reservoir under earthquake condition are calculated by using equivalent linear model and Shen Zhu-jiang’s residual deformation model.FindingsThe results show that with the increase of dynamic shear strain, the dynamic shear modulus decreases and the damping ratio increases. The scatter plot between dynamic shear modulus and dynamic shear strain, and the scatter plot between damping ratio and dynamic shear strain under different confining pressures show strips. The calculation results shows that the acceleration of embankment dam in Longyang Reservoir increases with the increase of dam height, and the acceleration distribution has obvious amplification effect. Combined with the maximum dynamic shear strain during the earthquake and the state before the earthquake, the maximum vertical residual deformation of embankment dam in Longyang Reservoir is 2.98 cm which occurs at the top of the dam, calculated by the Shen Zhu-jiang’s residual deformation model.Originality/value Finite element calculation model parameters of embankment dam are obtained by dynamic triaxial tests. Seismic dynamic responses and residual deformation of embankment dam are analyzed. With the increase of dam height, the acceleration distribution shows an obvious amplification effect. The vertical displacement of embankment dam is larger along the dam axis and decreases in the upstream and downstream direction. The maximum horizontal displacement of embankment dam occurs in the middle of upstream and downstream dam slopes.Highlights(1)Finite element calculation model parameters of embankment dam are obtained by dynamic triaxial tests.(2)Seismic dynamic responses and residual deformation of embankment dam are analyzed.(3)With the increase of dam height, the acceleration distribution shows an obvious amplification effect.(4)The vertical displacement of embankment dam is larger along the dam axis and decreases in the upstream and downstream direction.(5)The maximum horizontal displacement of embankment dam occurs in the middle of upstream and downstream dam slopes.

CT imaging‐enhanced numerical simulation of microscopic structure and resilient safety of asphalt concrete

AbstractAsphalt concrete is a foundational material in water conservancy projects, serving a critical function in the construction of impermeable structures such as dams. The seismic response characteristics and resilient safety of concrete dams are heavily influenced by the arrangement and evolution of the microscopic structure of the dam material. In this study, a high‐precision computed tomography (CT) scanning technique, in conjunction with advanced numerical simulations, was employed to analyze the internal damage and crack extension mechanism of asphalt concrete. Microstructural images of the asphalt concrete specimen were accurately captured by CT scanning, followed by the construction of corresponding numerical models. Presented simulation results show that the displacement deformation of asphalt concrete reaches its maximum value in the top region of the model and subsequently decreases with depth. Material damage was first observed at the interface between aggregate and asphalt matrix, where microcracks emerge and extend to the entire asphalt matrix, resulting in a gradual deterioration of the model performance. The simulation results indicate that the overall strength of asphalt concrete is primarily influenced by the strength characteristics of its aggregates. The stress–strain curves obtained from the numerical simulations exhibit a hyperbolic relationship, which is in high agreement with the physical test results. This study not only enhances our comprehension of the mechanical behavior of concrete but also contributes to the analysis of seismic response and risk assessment in dam engineering through dynamic experimental testing and numerical simulation.

Study on the changing law of three-dimensional electric field during the evolution of seepage field in earth and rock embankment dams

Seepage is a common disease of earth and rock embankment dams, but due to the complex geological conditions, its location and seepage diameter are more difficult to be accurately detected. In order to accurately determine the seepage damage state of earth and rock dam materials during the evolution of seepage field, and to clarify the change rule of three-dimensional electric field of earth and rock embankment dams during the evolution of seepage field, this paper establishes a correlation model between seepage field and electric field based on porosity. Based on the model, the relationship between resistivity and critical hydraulic ratio drop during the infiltration damage of soil and rock dam is determined, focusing on the study of the three-dimensional electric field in the infiltration process of soil and rock dam body with the seepage field change characteristics and change rules, and obtaining the electric field response characteristics of the seepage field of the different hidden bodies, which provides a diagnostic basis for the realization of the subsequent leakage diagnostic technology of soil and rock dams.

A new approach for identification of dispersivity class of soils by combining physical and chemical tests

The safety and performance of embankment dams after impounding water are highly related to the characteristics of the selected dam material. Impermeability is achieved by using clay soils as the core material in embankment dams. It has been observed that there are many collapsed dams, especially when dispersive soils with very low internal erosion resistance are used in the impermeable zone. For this reason, such soils should be determined at the design stage and not used in the construction of embankment dams. The dispersion mechanism is known to be controlled by clay mineralogy and cations in the pore fluid of soil. The physicochemical behaviour of the clay-water system is crucial to clarify the dispersion mechanism. Physical and chemical tests used for determining the dispersibility potential of soils are extensive and time-consuming methods. An alternative method has been proposed within the scope of this study. Three user-friendly and practical models based on Gene Expression Programming (GEP) were produced using chemical and double hydrometer test results to predict dispersion percentage (D%). In addition, a new classification criteria was proposed to identification of dispersivity class based on pinhole test data. If the dispersion percentage is less than 12% is soil is classified as non-dispersive, the dispersion percentage is between 12% and 30% and greater than 30%, it is defined as intermediate and dispersive, respectively. With this proposed criterion, more consistent and successful results were obtained for the dispersivity class.

Study on Wetting Deformation Characteristics of Damming Materials under Triaxial Compression

The wetting deformation of dam material will lead to uneven settlement of dam body, which will harm dam safety. A large static triaxial test instrument was used to conduct a single line triaxial compression humidification test on dam material in the main rockfill area of a power station. The humidification deformation rule and its relationship with confining pressure and stress level were analyzed. The experimental results show that the wetting axial strain is inversely proportional to the stress level, and the wetting volume strain is proportional to the confining pressure. The wetting model can effectively reflect the changing law of dam materials, and the research results provide experimental basis for the calculation and design of the dam body wetting deformation.

Design of shaft- and rim-driven contra-rotating reversible pump-turbine to optimize novel low-head pumped hydro energy storages

According to the European-Green-Deal, the share of renewable energy sources (RES) in electricity generation is increased by e.g. solar/wind. This requires the deployment of effective energy storage solutions to compensate the fluctuating network supply of RES. A well-developed storage technology is pumped hydro energy storage (PHES), but especially in lowland countries, e.g. Denmark, typical high-head plant locations are missing. Therefore, new developments in low-head hydraulic turbomachineries and smart operation schemes are needed to shape LH-PHES towards a viable future technology through maximizing performance and minimizing investment costs. Hence, this study demonstrates a novel design of contra-rotating, variable-speed, reversible pump-turbines (CR-VS-RPT) for low-head operation with a peak efficiency above 90 % in pump/turbine mode. The results comparing shaft-driven with rim-driven CR-VS-RPT show the influences of chosen RPT type on the reservoir size/investment. The study also proves that hydraulic losses due to the bulb for shaft-driven CR-VS-RPT have a decisive impact on the head range, and thus on the required dam material volume. Despite the slightly less efficient performance of rim-driven CR-VS-RPT, the absence of the bulb increases the efficiency during operation at low LATs. However, the LAT is the key factor for CR-VS-RPT type selection to minimize the investment for LH-PHES.

A 2D numerical model for simulating landslide dam failure and induced morphological changes considering multi-layer and non-uniform sediments

ABSTRACT Landslide dams are formed by the blockage of rivers with landslides or any debris flows. Such dams are prone to failure and therefore, simulation of their failure and induced morphological changes is of great importance for hazard mitigation. Multi-layer and non-uniform sediments are usually observed in landslide dam materials, but these are rarely considered in simulations. In this paper, a two-dimensional numerical model considering multi-layered and non-uniform sediments is proposed. The model solves the shallow water equations, the Exner equation considering the different size fractions and Hirano's active layer equation based on a finite volume scheme in a weakly coupled approach. Two experimental tests are used to assess the applicability and accuracy of the model. The results show that it can well simulate the flow and morphological changes, as well as the surface coarsening and fining phenomena related to multi-layer and non-uniform sediments. The numerical results of dam failure process and morphological changes are in overall good agreement with the experiments, but the peak discharge and bed elevation tend to be underestimated when finer material is considered. Finally, the influence of sediments fractions and active layer depth on numerical results, as well as the limitations of the model are discussed.

Experimental Study on Key Techniques for the Construction of High Asphalt Concrete Core Rockfill Dam under Unfavorable Geological Conditions

Asphalt concrete core dams (ACCDs) have been widely constructed in Xinjiang, yet the design of materials and structures has mainly relied on empirical knowledge without substantial theoretical grounding. In this study, we carried out a large-scale relative density test of gravel material in Bamudun dam, studied the compaction characteristics of gravel material, and determined the relative density characteristic index, in order to provide a basis for the subsequent dam material rolling test and construction quality inspection. Furthermore, in order to improve the efficiency of dam construction in narrow valleys, we optimized the connection type between asphalt concrete core wall and bedrock, and proposed a rapid construction method of paving core wall after pouring mass concrete base on bedrock. Finally, we established a three-dimensional finite element model to systematically analyze the stress and deformation patterns of the dam body, core wall, and base of the ACCD at Bamudun. The results show that the maximum compressive stress suffered by the core wall during the full storage period is 1.62 MPa, there is no tensile stress, and the risk of hydraulic splitting is small. The stress and deformation levels of each part are within the safe range. This verifies the rationality of the rapid construction method. The research findings can provide a great theoretical significance and engineering value for the safe design and construction of ACCDs.

Simulation of landslide dam failure due to overtopping considering vertical soil particles distribution

Accurate prediction of potential landslide dam breaches is crucial for timely and effective emergency responses to the resulting flood. Although many models for landslide dam overtopping have been proposed in past studies, most of these models did not consider the heterogeneity of dam materials, which is important in reflecting the erodibility of soil. In this study, a new mathematical model for landslide dam breaches due to overtopping was proposed based on a constructed vertical distribution model of dam particle size. Two real-world dams, the Tangjiashan landslide dam and Baige landslide dam, were used to evaluate the performance of the proposed model. In addition, the proposed model was compared with four existing dam failure models, and sensitivity analysis was conducted on the median particle size and particle size distribution. The results demonstrate that the computational outcomes of the proposed model align more closely with the actual results, indicating that the proposed model outperforms the four existing models in accurately simulating the landslide dam failure process. It also suggests that ignoring the variation of dam material particle size along the vertical direction inside the dam body would increase the prediction relative errors of key breach outcomes.

Erosion, deposition and breach evolution of landslide dams composed of various dam material types based on flume tests

The accurate and rapid prediction of breach outflow rates of landslide dams is crucial for effective risk assessment and mitigation strategies. However, challenges arise due to the complexities associated with breaching mechanisms. In this study, 12 flume tests were conducted on landslide dams composed of various material types, including fine-grained, coarse-grained, well-graded, and gap-graded materials, each with two dry densities. This study comprehensively investigated erosion, deposition, and breach evolution, providing the foundation for the development of breach evolution models. A comprehensive logic diagram, focusing on shear stress and grain size distribution, was proposed to forecast the failure modes of landslide dams. The study also suggested a method to assess the longitudinal breach evolution based on the prediction of the Erosion Point (EP) and Deposition Point (DP), and to assess the lateral breach evolution by considering both steep and gentle breach side slopes. Our findings indicate that fine-grained materials undergo layer erosion, coarse-grained materials remain stable, well-graded materials develop erosion pits, and gap-graded materials are prone to piping. The existence of an interface can result in piping channels, even when the overall hydraulic gradient is insufficient to initiate piping. Incorporating the longitudinal slope angle and its influence on both driving and resisting forces into the traditional erosion rate equation can significantly enhance its accuracy, especially when coarse particles are present. Coarse particles play a pivotal role in erosion and deposition behavior and reshaping the breach evolution as the initiation of coarse particles is dominated by rolling instead of slipping in fine particles. Deposition on the downstream slope of a dam can significantly influence the longitudinal breach process, leading to changes in the downstream topography and grain size distribution. The proposed method for assessing longitudinal breach evolution unifies the previous methodologies by predicting the positions of EP and DP based on erosion and deposition.

Numerical Analysis of Temperature and Stress Field of Side Dam on the Twin‐Roll Strip Casting

Side sealing technology is crucial in the twin‐roll casting process. The performance of side dam materials directly determines twin‐roll casting (TRC) process stability and safety. An orthogonal test is conducted to study the effects of thermal conductivity, linear expansion coefficient, and elastic modulus on the maximum thermal stress of side dams. The elastic modulus and linear expansion coefficient are identified as key factors affecting the maximum thermal stress of the side dam. The fluctuation of maximum thermal stress under different elastic modulus and linear expansion coefficients is 79.7 and 75.8 MPa, respectively, whereas it is only 11.2 MPa under different thermal conductivity. A side dam with heterogeneous material along height and thickness gradient is designed. The results indicate that the maximum thermal stress in the contact area between the side dam and the molten metal decreases to 31.2 MPa, representing a reduction of more than 30 MPa compared to the homogeneous side dam with optimal performance. The results provide important guidance in improving the stability of the TRC process.

Assessing the progress of internal instability of fill dam material in South Korea through long-term seepage tests

Several studies investigating the internal instability of well-graded soils have suggested that well-graded soils show characteristics and developments different from those of gap-graded soils. Moreover, the cause and progression of long-term internal instability in well-graded soils have not yet been established. This study aimed to address this knowledge gap by conducting long-term seepage tests to analyze the progress and cause of the internal instability of well-graded soils generally utilized in fill dams in South Korea. The test results revealed that well-graded soils in internally stable conditions exhibited clogging due to fine particles, reducing overall permeability. A similar phenomenon was identified under internally unstable conditions. The subsequent unclogging process resulted in a rapid increase in permeability and erosion rate with the collapse of the soil structure. Consequently, the internal instabilities of well-graded soils progress through suffosion. Based on the test results, the mechanism of internal instability and its progression in well-graded soils were proposed.

Compressive strength of manganese fine-grained material and molasses briquettes regarding binder content and curing time

In the production of raw materials for the manufacture of ferroalloys, up to 50% of the material mined is discarded as fine-grained tailings. Those tailings are deposited in dams, which are considered an environmental liability. To avoid this, an alternative would be to agglomerate the tailing dam materials using the briquetting process. Therefore, this work aims to evaluate the compressive strength of briquettes made of manganese fine-grained material (with particle size < 2.00 mm) and molasses regarding curing time and percentage of binder. To achieve the objective, 45 briquettes were made with fine-grained manganese ore, with 3 different molasses content (binder), these were put into 3 weeks of curing, to analyze the impact of binder content and curing time. The result was that the longer the curing time, the better the compressive strength and that increasing binder content reduces its compressive strength. Finally, the best results were obtained with 5 % binder and 3 weeks of curing time, in which the agglomerate produced had a compressive strength of 9,0 MPa.

Numerical Analysis and Experimental Study on Side Dam Temperature and Stress Field of Two‐Roll Casting

The side sealing technology is crucial for ensuring the quality and process stability in twin‐roll casting (TRC). Investigating the temperature and stress distribution in side dams under operational conditions is vital, especially in understanding the causes of side dam fractures. Optimal performance of side dam materials is achieved when the boron nitride (BN) matrix is fine and homogeneous, with zirconium dioxide (ZrO2) and silicon carbide (SiC) particles evenly dispersed throughout. The fracture of the side dam after casting is mainly caused by BN interlamellar tear. The coexistence of BN lamellar tearing and BN layer fracture leads to the fracture of the side dam during the casting process. Through finite element simulation, the effects of variables such as pouring temperature, preheating temperature, and side dam thickness on temperature and stress distribution were analyzed. The findings indicate that a preheating temperature range of 1200–1300 °C minimizes thermal stress in the side dam. Building on these findings, a composite structure for the side dam is developed. Both internal and external composite structures have shown significant effectiveness in reducing thermal stress. These results are pivotal in extending the service life of side dams and enhancing the stability of the TRC process.

Study on scale effect and particle crushing characteristics of continuously graded coarse-grained soil

The scale effect is an inevitable engineering challenge in dam construction, and the scale test is an effective means to characterize the dam material properties. In this article, the scale effect of the large coarse-grained soil is investigated based on physical and numerical tests. Firstly, the indoor and field compression test apparatuses are optimized to rectify the effect of barrel sidewall friction on the compressibility modulus during the tests. Then, the sample preparation standard for different scaled samples is determined by large-scale relative density tests in the field. Finally, based on indoor and field large-scale compression tests, the variation of the scale effect is investigated, and the particle crushing characteristics of the continuously graded aggregate sample are analyzed. The crushing characteristics of the continuously graded aggregate sample differ from those of the single-particle and the single size-group aggregate sample (a small range of particle sizes). Compression tests of the single-particle, single size-group aggregate, and continuously graded aggregate sample are characterized by overall splitting, overall splitting and local crushing, and local or angular crushing, respectively. The coordination number is the main reason for the difference in crushing characteristics of different test samples. The relationship between different particle sizes and strengths of continuously graded aggregate sample is investigated. The results of the study can provide a reference for recognizing the scale effect of large coarse-grained soils and evaluating compaction quality in the field.

Estimating the Peak Outflow and Maximum Erosion Rate during the Breach of Embankment Dam

Understanding and modeling a dam breaching process is an essential investigation, because it aims to minimize the flood’s hazards, and its impact on people and structures, using suitable mitigation plans. In the current study, three-dimensional numerical modeling is carried out using the FLOW-3D HYDRO program to investigate the impact of various factors, including the dam grain size materials, crest width, inflow discharge, and tail water depth on the dam breach process, particularly the peak outflow, and the erosion rate. The results show that changing the grain size of the dam material from fine sand to medium and coarse sand leads to an increase in the peak outflow discharge by 16.0% and the maximum erosion rate by 20.0%. Furthermore, increasing the dam crest width by 40% leads to a decrease in the peak outflow by 3.0% and the maximum erosion rates by 4.50%. Moreover, increasing the inflow discharge by 25.0% increases the peak outflow by 23.0% and the maximum erosion rates by 21.0%. Finally, increasing the tail water depth by 50.0% leads to decreasing the peak outflow by 4.50% and the maximum erosion rate by 43.0%. The study findings are considered of high importance for dam design and operation control. Moreover, the results can be applied for the optimum determination of the crest width and tail water depth that leads to improving the dam stability.

Numerical Analysis of the Overtopping Failure of the Tailings Dam Model Based on Inception Similarity Optimization

The analysis of overtopping dam break caused by extreme rainstorms and other special circumstances is very important in the feasibility analysis of new construction or expansion projects of tailings reservoirs. Reduced-scale physical model tests can directly reflect the topography and dam-break influence range, but the reasonable selection of model dam material is the key to ensure the model’s similarity. Based on the similarity optimization of the limit state of scour inception of sediment particles, a new method for the model material of tailings dams can be proposed, but it needs to be verified by a similar overtopping model test. In this paper, the modeling and numerical calculation analysis of a prototype tailings dam and a similar reduced-scale model are carried out by using FLOW-3D v11.2 numerical software. The calculation results show that the model test scheme optimized by inception similarity can well reproduce the overtopping failure process of the prototype dam.

Study on Impoundment Deformation Characteristics and Crack of High Core Rockfill Dam Based on Inversion Parameters

In the numerical simulation of earth-rock dam, accurate and reliable mechanical parameters of the dam material are the important basis for dam deformation predictions and dam safety evaluations. Based on the deformation monitoring data of Luding core wall rockfill dam, the rheological parameters of rockfill and core wall materials are inverted in this paper. Combined with the actual filling and impoundment process of the dam, the numerical simulation is carried out, and the stress deformation and differential settlement of the dam after completion and impoundment are analyzed. The results showed that the stress deformation results of the dam based on the inversion parameters were in good agreement with the actual deformation. The horizontal displacement, settlement, and principal stress of the dam during the completion period were symmetrically distributed along the core wall. The maximum horizontal displacement occurred at the main dam on both sides of the core wall and the upstream and downstream dam slopes, and the maximum settlement occurred in the middle of the core wall. During the impoundment period, under the action of reservoir water pressure and upstream rockfill wetting deformation, the deformation and stress of the dam body no longer met the symmetrical distribution law, and the maximum horizontal displacement of the dam body during the impoundment period was located at 2/3 of the upstream dam slope. The maximum settlement of the dam body was located at 1/2 of the dam height. The maximum principal stress on the upstream side of the core wall was located on the left side of the bottom of the core wall, and the minimum principal stress was also located on the left side of the bottom of the core wall. The simulation results of the deformation and stress met the general law of earth-rock dam engineering. During the completion period, the deformation inclination of the dam crest was less than 1%. During the impoundment period, the deformation inclination of the dam crest area increased due to the wetting deformation of the upstream rockfill material. At the same time, the deformation inclination of the dam crest axis was larger than that of the upstream and downstream sides, and the deformation inclination of the dam crest at the middle of the valley was the largest, but it did not exceed 3%, that is, there would be no longitudinal cracks, which is consistent with the actual situation. The research results can better predict the stress deformation and crack of the dam body, and provide important support for dam safety evaluations.

Analyzing stability of protective structures as the elements of geotechnical tailing pond safety

Purpose is the assessment of soil retaining wall stability to ensure geotechnical safety during the radioactive waste tailing pond closure and further recultivation (or rehabilitation) in Kamianske town (Ukraine). Methods. Geomechanical stability of the protective structure has been assessed relying upon the analysis of geological-hydrogeological, engineering-geological, and geotechnical conditions of the certain tailing pond area using a deformation elastic-plastic model of a medium implemented on the basis of finite-element method. For the purpose, the dam slopes have been detalized taking into consideration their geometry as well as changes in vertical section of rock material characteristics in accordance with the earlier geophysical studies; exploration drilling; and engineering-geological surveys. Findings. Stability coefficients of protective tailing pond dam have been identified within the typical areas of a hydraulic structure; it provides high reliability and representativeness of the whole structure health in time as well as under various conditions of the industrial waste water saturation. It has been defined that the stability coefficients varies from ks = 1.372 to 4.758. Comparison of the indicators between 2022 and 2016 demonstrates a tendency of the slope stability coefficient decrease due to water saturation and groundwater level rise. Nevertheless, design characteristics of the structure make it possible to ensure satisfactory a stability coefficient along the whole dam length being 1.13 times higher than the standard one (i.e. ks = 1.250). Originality. The dependence of the tailing pond protective dam stability upon a water supply degree at the forecasted groundwater level rise at the expense of atmospheric and melt water ingress to the tailing pond has been defined. The danger of complete radioactive waste water saturation is a significant reduction in the stability coefficient of the protective structure, which can be supported by predictive modelling data. If strength parameters of a dam material decline for the most critical area then the strength coefficient decreases starting from 1.532 in terms of the current groundwater level down to 1.372 as for the forecasted dam water supply. The figure is more than 10% of its initial stability. Practical implications. The obtained results substantiate the necessity; moreover, they are of practical value while improving hydrological, hydrogeological, and geotechnical monitoring of the analyzed tailing pond to ensure its radiation safety under different conditions of further behaviour during closure, recultivation, or rehabilitation.

Longevity prediction and influencing factor analysis of landslide dams

The longevity prediction and analysis of landslide dams are significant for evaluating the failure risks and formulating emergency plans. However, owing to the large range of landslide dam longevity (from “minutes” to “millennia”), both the analysis of influencing factors within different longevity ranges and a reliable longevity prediction model are still challenging. Based on 1045 landslide dam cases, the statistical analysis of the available data and longevity records is conducted. The landslide dam longevity is classified into seven categories (L1: <1 h, L2: 1 h to 1 day, L3: 1 day to 1 week, L4: 1 week to 1 month, L5: 1 month to 6 months, L6: 6 months to 1 year, and L7: >1 year). The k-Nearest Neighbor algorithm is used to impute the missing data for each longevity category. Based on geometric parameters (dam height, length, width, and volume), hydrological parameters (dammed lake volume and upstream catchment area), triggers, and dam materials, a longevity category classification model and a longevity numeric regression model are developed. The former is established for estimating the longevity range of landslide dams with an accuracy of 91%, and the latter is constructed with an R2 value of 0.95 for predicting precise longevity. Furthermore, the application of longevity prediction models proposed in this paper is verified by three landslide dam cases with reliable recorded data in the recent few years, while their predictive performance is also compared with that of conventional statistical models. Based on the SHapley Additive exPlanations attribution theory, the importance of geometric/hydrological parameters, triggers, and dam materials in determining the longevity of landslide dams in each longevity category is demonstrated using the complete database. Additionally, the influence level of each input variable on the prediction results is analyzed by examining the specific cases. The results indicate that the models proposed in this paper are superior to conventional statistical models in applicability and prediction accuracy. Notably, geometric parameters serve as the most important factor in each longevity category. Generally, the hydrological parameters can be regarded as the second most important factor in terms of influencing the longevity of landslide dams, while dam material demonstrates the lowest impact. The impact of triggers is more significant for landslide dams with a longevity of < 1 day. For landslide dams with a longevity exceeding one month, the importance of hydrological parameters is more prominent. Analyzing the impact of input variables on the prediction results of the specific landslide dams can facilitate the identification of key factors and provide some preliminary guidance for emergency rescue efforts.