Acta Geotechnica最新文献_第9页

Effect of stress conditions on concentrated leak erosion resistant of fine-grained soils with different characteristics 应力条件对不同特性细粒土抗集中渗漏侵蚀性的影响

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-08-12 DOI: 10.1007/s11440-024-02376-y

Sadettin Topçu, Hasan Savaş, Hasan Tosun

{"title":"Effect of stress conditions on concentrated leak erosion resistant of fine-grained soils with different characteristics","authors":"Sadettin Topçu, Hasan Savaş, Hasan Tosun","doi":"10.1007/s11440-024-02376-y","DOIUrl":"10.1007/s11440-024-02376-y","url":null,"abstract":"<div><p>Internal erosion is one of the most important factors that cause earth structures that retain water, such as embankment dams, to collapse. Concentrated leak erosion, one of the forms of internal erosion, occurs in cracked fine-grained soils and pressurized flow conditions. To evaluate the concentrated leak erosion risk of cracks/voids, it is necessary to ascertain the erosion resistance of these materials. The erosion rate and critical shear stresses determine internal erosion resistance in concentrated leak erosion. This study determined soil’s concentrated leak erosion resistance using test equipment that allowed the flow to pass through a hole with stress-free (no loading), anisotropic-compression stress, anisotropic-expansion stress, and isotropic stress conditions. The stresses that developed in the samples’ hole wall where erosion occurred were determined with numerical modeling as pre-experimental stress conditions. The experiments were performed under a single hydraulic head on four selected cohesive soils with different erosion sensitivity. Time-dependent flow rates obtained from the test system can be used to determine hydraulic parameters, such as energy grade lines, with the help of basic theorems of pipe hydraulics in theoretical hydraulic models. Moreover, the erosion rates were quantitatively determined using the continuity equation, while critical shear stresses were qualitatively compared for concentrated leak erosion developed by the dispersion mechanism. As a result of the experiments, stress conditions influence the concentrated leak erosion resistance in the soil samples with dispersive erosion. Moreover, the shear strength in the Mohr–Coulomb hypothesis can explain the erosion resistance in these soils under stress conditions depending on the sand/clay ratio.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"7967 - 7988"},"PeriodicalIF":5.6,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02376-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling of granular materials at crushing-dominant stage 颗粒物料在破碎主导阶段的建模

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-08-09 DOI: 10.1007/s11440-024-02383-z

Yaolan Tang, Chunshun Zhang, Congying Li, Weiru Zhou, Junfeng Qian, Jian Zhao

{"title":"Modelling of granular materials at crushing-dominant stage","authors":"Yaolan Tang, Chunshun Zhang, Congying Li, Weiru Zhou, Junfeng Qian, Jian Zhao","doi":"10.1007/s11440-024-02383-z","DOIUrl":"10.1007/s11440-024-02383-z","url":null,"abstract":"<div><p>Granular crushing significantly changes mechanical behaviours, especially under elevated stress levels. Therefore, this study aims to develop a model to simulate the constitutive behaviours of granular materials at the crushing-dominant stage. Firstly, the contour of elastic potential energy is demonstrated and employed to derive the yield surface or function, acknowledging that the stored elastic energy dominates the breakage yield criterion. The versatility of the proposed yield function in accurately capturing the features of yield surfaces is verified with three cases, including Cam-clay models, test results, and an empirical yield function. Next, a hardening parameter, <i>H</i>, is formulated, considering the extent of crushing, <i>B</i>, and the void ratio, <i>e</i>, to reflect the expansion of the yield surface during hardening. The proposed simple hardening formulation favourably represents compression characteristics under elevated stress levels. Combining the above results of yield and hardening functions, a new elastic–plastic-crushing constitutive model is developed; the model’s capability to describe crushable granular material behaviours is validated against experimental counterparts.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6535 - 6551"},"PeriodicalIF":5.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Grouting mechanism of quick-setting slurry in fracture with random fracture opening considering time–space characteristics of viscosity 考虑粘度时空特性的随机断裂口中速凝浆液的灌浆机理

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-08-07 DOI: 10.1007/s11440-024-02378-w

Shu Zhu, Jianfu Shao, Hexuan Zhu, Zhende Zhu, Feiyang Wang, Junyu Wu

{"title":"Grouting mechanism of quick-setting slurry in fracture with random fracture opening considering time–space characteristics of viscosity","authors":"Shu Zhu, Jianfu Shao, Hexuan Zhu, Zhende Zhu, Feiyang Wang, Junyu Wu","doi":"10.1007/s11440-024-02378-w","DOIUrl":"10.1007/s11440-024-02378-w","url":null,"abstract":"<div><p>The coupling effect between the spatial variability of slurry diffusion and the time-varying viscosity of quick-setting slurry is the time–space characteristics of slurry viscosity (TSCSV). The TSCSV is the governing factor for the complex and uncontrollable flow of slurry in fractures. In this regard, the flow pattern of quick-setting slurry is considered as a Bingham fluid with viscosity spatiotemporal characteristics. Using the fractal function with random parameters (W-M function), a single fracture with random fracture opening (RFO) is drawn, and a theoretical model on grouting diffusion in fractures is established considering the TSCSV. The RFO is corrected for head loss, and the spatiotemporal distribution equation of the RFO grouting pressure is derived. The relationship between grouting pressure, grouting time, and slurry diffusion distance is obtained. Additionally, the effects of the RFO, the fractal dimension of the fracture curve, the horizontal movement distance of the lower end face of the fracture, and the effects of viscosity and grouting rate on the viscosity and grouting pressure in the slurry diffusion space are discussed. Finally, by predefining the spatial distribution function of slurry viscosity for a single fracture in the numerical calculation model, a numerical simulation of random fracture distribution grouting considering viscosity spatiotemporal characteristics is achieved. The rationality of the model is validated through a comparison of theoretical analysis and numerical simulation, providing reference for the determination of grouting parameters in practical grouting projects.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6517 - 6534"},"PeriodicalIF":5.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141941898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Important considerations in machine learning-based landslide susceptibility assessment under future climate conditions 未来气候条件下基于机器学习的滑坡易发性评估的重要考虑因素

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-08-03 DOI: 10.1007/s11440-024-02363-3

Yi Han, Shabnam J. Semnani

{"title":"Important considerations in machine learning-based landslide susceptibility assessment under future climate conditions","authors":"Yi Han, Shabnam J. Semnani","doi":"10.1007/s11440-024-02363-3","DOIUrl":"10.1007/s11440-024-02363-3","url":null,"abstract":"<div><p>Rainfall-induced landslides have caused a large amount of economic losses and casualties over the years. Machine learning techniques have been widely applied in recent years to assess landslide susceptibility over regions of interest. However, a number of challenges limit the reliability and performance of machine learning-based landslide models. In particular, class imbalance in the dataset, selection of landslide conditioning factors, and potential extrapolation problems for landslide prediction under future conditions need to be carefully addressed. In this work, we introduce methodologies to address these challenges using XGBoost to train the landslide prediction model. Data resampling techniques are adopted to improve the model performance with the imbalanced dataset. Various models are trained and their performances are evaluated using a combination of different metrics. The results show that synthetic minority oversampling technique combined with the proposed gridded hyperspace sampling technique performs better than the other imbalance learning techniques with XGBoost. Subsequently, the extrapolation performance of the XGBoost model is evaluated, showing that the predictions remain valid for the projected climate conditions. As a case study, landslide susceptibility maps in California, USA are generated using the developed model and are compared with the historical California landslide catalog. These results suggest that the developed model can be of great significance in global landslide susceptibility mapping under climate change scenarios.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"475 - 500"},"PeriodicalIF":5.6,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02363-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compression and critical-state behaviors of calcareous sand–diatom mixtures 钙质砂硅藻混合物的压缩和临界状态行为

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-31 DOI: 10.1007/s11440-024-02365-1

Yang Xiao, Haoran Yang, Shuang Liu, Qingyun Fang, Hao Cui, Hanlong Liu

{"title":"Compression and critical-state behaviors of calcareous sand–diatom mixtures","authors":"Yang Xiao, Haoran Yang, Shuang Liu, Qingyun Fang, Hao Cui, Hanlong Liu","doi":"10.1007/s11440-024-02365-1","DOIUrl":"10.1007/s11440-024-02365-1","url":null,"abstract":"<div><p>Calcareous sand–diatom mixtures are found naturally in the coral reef sediments, where the diatom potentially affects the mechanical behaviors of the mixtures. We performed a series of isotropic compression and triaxial drained shear tests to investigate the effect of diatom on the compression and critical-state behaviors of the mixtures. We found that the diatom and effective confining pressure can considerably affect the compression index, swelling index, coefficient of volume compressibility, compression modulus, secant modulus, peak-state deviatoric stress, peak-state axial strain, and peak-state frictional angle. In addition, the critical-state friction angle is independent of the diatom content, while the critical-state line (CSL) in the compression plane is affected significantly by the diatom content. We proposed modified equations for compression modulus and CSL considering the influence of diatom content, and the two equations could reasonably predict the compression deformation and critical-state behaviors of the mixtures. This study provides experimental basis for understanding critical-state behavior for the calcareous sand–diatom mixtures.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"119 - 129"},"PeriodicalIF":5.6,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of non-erodible particle content on the mechanism of suffusion and the evolution of permeability of sandy soil 不腐烂颗粒含量对砂土窒息机制和渗透性演变的影响

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-27 DOI: 10.1007/s11440-024-02375-z

Jie Kang, Jie Ren, Songtao Hu, Hengle Guo, Kaixuan Chen, Ting Zhuang, Shenghao Nan, Jiaheng Sui

{"title":"Effect of non-erodible particle content on the mechanism of suffusion and the evolution of permeability of sandy soil","authors":"Jie Kang, Jie Ren, Songtao Hu, Hengle Guo, Kaixuan Chen, Ting Zhuang, Shenghao Nan, Jiaheng Sui","doi":"10.1007/s11440-024-02375-z","DOIUrl":"10.1007/s11440-024-02375-z","url":null,"abstract":"<div><p>Suffusion is a typical type of internal erosion that is an important factor leading to the failure of dams and dikes. In this paper, fine particles are divided into erodible particles and non-erodible particles, and the soil suffusion mechanism is investigated by laboratory tests and CFD_DEM simulations when the content of erodible particles (<i>F</i><sub>c</sub>) and non-erodible particles (<i>F</i><sub>z</sub>) is 15% and 5%, 10% and 10%, and 5% and 15%. The global mean permeability coefficient (<i>k</i><sub>av</sub>) and local permeability coefficient (<i>k</i><sub>i–j</sub>) were calculated by monitoring the water head in the seepage path of the sample. The results show that with increasing non-erodible particle content, the difficulty of soil suffusion increases gradually. When soil suffusion occurs, the loss of fine particles starts from the seepage outlet area and the influent area, and the non-erodible particles have little influence on the particle loss process in these two areas. After the occurrence of suffusion, the number of weak contact chains is obviously reduced, while the strong contact chains are basically stable. When <i>F</i><sub>z</sub> = 5% and <i>F</i><sub>z</sub> = 10%, the average permeability coefficient of the soil after suffusion expands to 2.21–1.60 times that of the initial state, and the corresponding values of the CFD_DEM simulation are 2.14–1.86 times.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"8147 - 8164"},"PeriodicalIF":5.6,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A gradation-dependent hypoplastic model for crushable sands 可碾压砂的分级次塑性模型

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-27 DOI: 10.1007/s11440-024-02372-2

Yaolan Tang, Shun Wang, Chunshun Zhang

引用次数: 0

Analytical approach for lateral dynamic behaviours of pipe piles enhanced by cement-improved soil in unsaturated ground 非饱和地层中水泥改良土增强管桩横向动力行为的分析方法

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-26 DOI: 10.1007/s11440-024-02373-1

Hongbo Liu, Guoliang Dai, Fengxi Zhou, Haoran OuYang, Jun Liu

{"title":"Analytical approach for lateral dynamic behaviours of pipe piles enhanced by cement-improved soil in unsaturated ground","authors":"Hongbo Liu, Guoliang Dai, Fengxi Zhou, Haoran OuYang, Jun Liu","doi":"10.1007/s11440-024-02373-1","DOIUrl":"10.1007/s11440-024-02373-1","url":null,"abstract":"<div><p>Pipe piles enhanced by cement-improved soil (hereinafter referred to as enhanced pipe piles) have excellent bearing capacity compared with traditional piles and are often used as the foundation of offshore wind turbines and coastal soft-soil embankment. This study aims to clarify and gain an insight into the lateral dynamic response of enhanced pipe piles in unsaturated soil by developing an analytical approach. In the proposed approach, the enhanced pipe pile divides into two parts: The first part is considered as a composite pile formed by a concrete pipe pile and a cement-soil mixing pile through high-strength bonding, and the second part formed by a concrete pipe pile and an unsaturated soil column. The lateral vibration behaviours of the enhanced pipe pile and the unsaturated soil resistance are deduced by the Euler–Bernoulli beam theory and the porous viscoelastic theory of three-phase mixture, respectively. The closed-form solutions for the horizontal, rocking and horizontal-rocking dynamic impedances at the pile head of enhanced pipe pile under horizontal dynamic loads have been determined and then validated by comparing with the existing results. Numerical discussions are finally conducted to analysis the influence of physical parameters of enhanced pipe pile and unsaturated soil on the three types of dynamic impedance at the pile head. The main findings can be summarized as: (a) For the cement-soil mixing pile, its length should not exceed half of the concrete pipe pile, its radius size should be moderate and its elastic modulus can be as large as possible; (b) the wall thickness and elastic modulus of the concrete pipe pile can be appropriately increased to make the enhanced pipe pile achieve better vibration resistance and (c) the increase of the soil saturation will reduce the anti-vibration ability of enhanced pipe piles.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6747 - 6772"},"PeriodicalIF":5.6,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Response of anisotropy modeled compacted embankment during infiltration 各向异性模型压实路堤在渗透过程中的反应

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-22 DOI: 10.1007/s11440-024-02374-0

Rakshanda Showkat, G. L. Sivakumar Babu

{"title":"Response of anisotropy modeled compacted embankment during infiltration","authors":"Rakshanda Showkat, G. L. Sivakumar Babu","doi":"10.1007/s11440-024-02374-0","DOIUrl":"10.1007/s11440-024-02374-0","url":null,"abstract":"<div><p>During rainfall, collapse compression predominates due to the slippage of particles, resulting in the rearrangement of soil fabric toward a configuration dependent on the fabric of the initial stress state. Consequently, these alterations in soil fabric induce anisotropic mechanical behavior in unsaturated soils. In this study, an anisotropic model, denoted as ABBM and based on the Barcelona Basic Model (BBM), was implemented into FLAC to analyze the wetting behavior of a typical compacted embankment during infiltration. The research findings indicate that prolonged rainfall durations result in the evolution of the yield surface, consequently amplifying vertical surface displacement. Moreover, as the anisotropic evolution parameter surpasses a defined threshold, the degree of anisotropy diminishes, ultimately resembling the isotropic behavior observed in the Barcelona Basic Model (BBM) due to changes in preconsolidation pressure. The study presents an innovative approach to evaluate embankment performance under rainfall-induced conditions by considering changes in fabric anisotropy relative to the degree of saturation. The results demonstrate that alterations in the degree of saturation lead to rotation of the yield surface, nearly erasing anisotropy upon reaching full saturation. To account for parameter variability, a reliability analysis was performed using the Monte Carlo method, assessing the performance of embankment using different constitutive models, viz, the Mohr–Coulomb model, BBM, and ABBM. Notably, the analysis revealed that embankment failure probabilities simulated using the ABBM exceed those obtained using the Mohr–Coulomb criterion or BBM, suggesting a greater susceptibility to failure in terms of deformations. This observation has practical significance in a sense that use of appropriate constitutive models in embankments is required.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"8129 - 8146"},"PeriodicalIF":5.6,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Particle-scale study on backward erosion of multilayer erodible medium under converging flow: experimental tests and numerical modelling 汇流条件下多层可侵蚀介质逆向侵蚀的粒子尺度研究：实验测试与数值模拟

IF 5.6 1区工程技术

Acta Geotechnica Pub Date : 2024-07-20 DOI: 10.1007/s11440-024-02370-4

Gang Zheng, Zhitong Chen, Tianqi Zhang, Huimin Qiu, Ke Wang, Yu Diao

{"title":"Particle-scale study on backward erosion of multilayer erodible medium under converging flow: experimental tests and numerical modelling","authors":"Gang Zheng, Zhitong Chen, Tianqi Zhang, Huimin Qiu, Ke Wang, Yu Diao","doi":"10.1007/s11440-024-02370-4","DOIUrl":"10.1007/s11440-024-02370-4","url":null,"abstract":"<div><p>Leakage at the bottom of an underground structure can compel ground water to form a converging flow, under which soil erosion may occur, thereby threatening the safety of the structure. Previous studies have shown that converging flow may induce backward erosion, and unravelling the mechanism behind this type of erosion was pivotal to mitigating disasters in practical engineering. Existing studies on this topic have been limited to monolayer erodible medium, while the mechanism behind the backward erosion of a multilayer erodible medium under converging flow remains unclear. In this study, both experimental tests and numerical simulations based on the validated computational fluid dynamics and the discrete element coupling method (CFD–DEM) were conducted to investigate the backward erosion of a multilayer sample under converging flow. The results demonstrated that the multilayer sample was eroded layer-by-layer, whereby residual layers could be observed at the bottom of the sample. The eroded regions in different layers were similar in shape but smaller in size for lower layers. In addition, particle exchange occurred among different layers during the erosion process. In general, lower-layer particles could directly ascend to upper layers in the eroded regions, whereas upper-layer particles mainly settled on the periphery of the eroded regions.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"7075 - 7087"},"PeriodicalIF":5.6,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141737500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0