Acta Geotechnica最新文献

{"title":"Mesoscale simulation of the compression and small-strain elastic shear behavior of illite nanoparticle assemblies","authors":"Hejian Zhu,&nbsp;Andrew J. Whittle,&nbsp;Roland J.-M. Pellenq","doi":"10.1007/s11440-024-02440-7","DOIUrl":"10.1007/s11440-024-02440-7","url":null,"abstract":"<div><p>The mechanical properties of clay minerals are largely dependent upon the chemical compositions and the mesoscale fabrics of the constituent particles. This paper describes results of a series of mesoscale molecular dynamics simulations of the hydrostatic compression and shear strain behavior for initially randomly oriented assemblies of 10³ illite primary particles. The particles are simulated as rigid-body ellipsoids that interact through the single-site, Gay–Berne potential function. This corresponds to a coarse-grained model based on prior atomistic scale computation of the potential of mean force for water-mediated interactions between pairs of particles through free energy perturbation method. We investigate the mesoscale fabrics of the NPT-equilibrated assemblies for confining pressures ranging from 1.0 to 125 atm, including path dependence associated with unloading and reloading. We analyze and quantify the geometric arrangement including particle orientation, specific surface area, properties of particle stacks/aggregates, and interstack pair correlation functions. The compression of each particle assembly is associated with large irrecoverable changes in void ratio, while unloading and reloading involves much smaller, largely recoverable volumetric strains. The results are qualitatively similar to macroscopic compression behavior reported in laboratory tests. We simulate the uniaxial and shear behavior at each of the equilibrated pressure states through a series of strain-controlled steps, allowing full relaxation of the virial stresses computed at each step. The simulations investigate directional and path dependence of the shear behavior for strain deviations up to 0.2%. The results show the onset on nonlinear stiffness properties at strain levels <span>(sim)</span>0.01% and hysteretic behavior upon unloading and reloading. Small-strain stiffness properties of the particle assemblies are qualitatively in good agreement with quasi-static, elastic stiffness properties reported for illitic clays.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"781 - 802"},"PeriodicalIF":5.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362109","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}

{"title":"Large-scale testing to assess the performance of biogeochemical and soil cover systems for landfill gas mitigation","authors":"Gaurav Verma,&nbsp;Jyoti K. Chetri,&nbsp;Krishna R. Reddy,&nbsp;Stefan J. Green","doi":"10.1007/s11440-024-02511-9","DOIUrl":"10.1007/s11440-024-02511-9","url":null,"abstract":"<div><p>Fugitive emissions of methane (CH₄), carbon dioxide (CO₂), and hydrogen sulfide (H₂S) from municipal solid waste landfills are major environmental concerns. To address this, a biogeochemical cover (BGCC) system is developed to mitigate these emissions. This study evaluates the effectiveness of the BGCC in comparison with a conventional soil cover (SC) system using a new large-scale laboratory setup that simulates near-field scale conditions. Both cover systems were exposed to synthetic landfill gas (LFG) across five phases, featuring varying gas compositions and influx rates. Surface emission rates and gas concentrations were continuously monitored. Post-termination of the experiments, both cover systems were dismantled, and samples were collected from different depths and locations to analyze spatial variations in physico-chemical properties. Select samples from the biocover layer of both the cover systems and basic oxygen furnace (BOF) slag layer of BGCC were subjected to batch tests to measure potential CH₄ oxidation rates and residual carbonation capacity, respectively. The results showed that both cover systems achieved their highest CH₄ removal efficiency at moderate influx rates (23.9–25.5 g CH₄/m²-day), with BGCC's CH₄ removal ranging from 74.7 to 79.7% and SC's from 83.5 to 99.8%. Complete H₂S removal occurred in the biocover layer of both systems. The highest average CH₄ oxidation rates were 277.9 µg CH₄/g-day at 50 cm below-ground surface (bgs) in BGCC and 260.2 µg CH₄/g-day at 70 cm bgs in SC, with the lowest oxidation rates observed at deeper regions (at 85 cm bgs) of both covers. The breakthrough of CO₂ occurred after 156 days of continuous exposure and could be attributed to the desiccation of the BOF slag layer. Overall, the BGCC system effectively mitigated CH₄, CO₂, and H₂S emissions, whereas the SC system only mitigated CH₄ and H₂S at moderate flux rates, indicating that BGCC provides a comprehensive solution for LFG mitigation.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1471 - 1494"},"PeriodicalIF":5.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571152","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}

{"title":"DEM parameter calibration based on multi-objective Bayesian optimization and prior physical information","authors":"Ni An,&nbsp;Guanqi Wang,&nbsp;Di Wang,&nbsp;Gang Ma,&nbsp;Xiaolin Chang,&nbsp;Wei Zhou","doi":"10.1007/s11440-025-02537-7","DOIUrl":"10.1007/s11440-025-02537-7","url":null,"abstract":"<div><p>The discrete element method (DEM) is proving to be a reliable tool for studying the behavior of granular materials and has been increasingly used in recent years. The accuracy of a DEM model depends heavily on the accuracy of the particle property parameters chosen which is of vital importance for studying the mechanical properties of granular materials. However, the existing DEM parameter calibration methods are limited in terms of applicability, and the trial-and-error method remains the most common way for DEM parameter calibration. This paper presents a novel calibration method for DEM parameters using the multi-objective tree-structured parzen estimator algorithm based on prior physical information (MOTPE-PPI). The MOTPE-PPI does not rely on the training datasets and may optimize with every single test, significantly reducing the computational efforts for DEM simulation. Moreover, MOTPE-PPI is suitable for a variety of contact models and damping parameters in DEM simulation, showing robust applicability and practical feasibility. Taking an example, the DEM parameters of sandy gravel material collected from Dashixia rockfill dam in China are calibrated using MOTPE-PPI in the paper. The prior physical information is obtained through a series of triaxial loading–unloading tests, single-particle crushing tests, and literature research. Seven parameters in the rolling resistance linear contact model and breakage model are considered, and the optimization process takes only 25 iterations. Through quantitative comparison with existing parameter calibration methods, the high efficiency and wide applicability of the DEM parameter calibration method proposed in this study. The calibrated DEM parameters are used to investigate the hysteretic behavior and deformation characteristics of the granular material, revealing that the accumulation of plastic strain and resilient modulus is related to confining pressure, stress level, and the number of cycles.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1379 - 1401"},"PeriodicalIF":5.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571151","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}

{"title":"Sand stiffness variability induced by stochastic distributions of calcite precipitates: a Monte Carlo-DEM study","authors":"Meng Sun,&nbsp;Pengfei Liu,&nbsp;Yuxuan Chen,&nbsp;Bate Bate,&nbsp;Fan Xue","doi":"10.1007/s11440-025-02539-5","DOIUrl":"10.1007/s11440-025-02539-5","url":null,"abstract":"<div><p>The inclusion of calcite precipitates (CaCO₃) in soft soil can improve the mechanical properties. Understanding the variability in sand stiffness due to heterogeneous precipitates is crucial for stiffness evaluation and prediction. A novel discrete element-Monte Carlo (DE-MC) method was proposed to quantify the sand stiffness variability induced by stochastic distributions of calcite precipitates, specifically focusing on shear wave velocity (<i>V</i>_s) as an indicator of soil stiffness. A total of 1972 samples were constructed to simulate stochastic spatial distributions of calcite precipitates. Through joint stochastic analysis, the preferential paths formed by calcite clusters were identified as significant contributors to <i>V</i>_s variability. The normalized connectivity per unity distance contact weight (<i>C</i>_<i>d,n</i>) exhibited the most correlated relation with <i>V</i>_s. Two weight selection methods were applicable for using <i>C</i>_<i>d,n</i> to characterize and predict <i>V</i>_s. The results suggest that the DE-MC method has the potential to assess the variability in sand stiffness quantitatively.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1363 - 1377"},"PeriodicalIF":5.6,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571096","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}

{"title":"A chemo-mechanical model of the swelling of anhydritic claystones","authors":"Antonia Nousiou,&nbsp;Georgios Anagnostou","doi":"10.1007/s11440-024-02447-0","DOIUrl":"10.1007/s11440-024-02447-0","url":null,"abstract":"<div><p>Anhydritic claystones are widely distributed in the Gypsum Keuper formation. Their swelling is associated with the chemical process of anhydrite to gypsum transformation and has caused extensive damages in tunnels. Even though this problem has attracted great scientific interest, an adequate mathematical description of the swelling of anhydritic rocks is still missing. The present paper contributes towards closing this gap by formulating a coupled chemo-mechanical constitutive model, which considers anhydritic rock as an elastoplastic porous medium according to the principle of effective stresses, with a Mohr–Coulomb yield criterion, a non-associated flow rule and an additional, chemically induced strain component. The volumetric chemical strain is equal to the sum of the changes of the volume of the solids and of the pore volume. The change of the volume of the solids depends on the stoichiometry of the chemical reaction and is proportional to the mass of the transformed anhydrite. The pore volume may increase or decrease during the anhydrite to gypsum transformation, depending on how gypsum grows. The pore volume increases if the gypsum crystals crack and expand the matrix, and decreases if the gypsum crystals precipitate within the available pore space. The proposed model considers experimental results according to which the higher the stresses and porosity, the lower the increase in pore volume. In addition, the model assumes that the chemical strains are coaxial with the principal stresses and that the volumetric chemical strain in each principal direction is inversely proportional to the corresponding principal stress. The model is calibrated with results of tests on artificial anhydrite-kaolin specimens and achieves a very high correlation degree (<i>R</i>^<i>2</i> = 0.92).</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"823 - 841"},"PeriodicalIF":5.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02447-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361990","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}

{"title":"On-site test of fixed mobile sand dunes using combined technology of sand plants and EICP in the Ulanbuh Desert, China","authors":"Chi Li,&nbsp;Shuanhu Li,&nbsp;Jiawei Xing,&nbsp;Yu Gao,&nbsp;De Yao","doi":"10.1007/s11440-024-02524-4","DOIUrl":"10.1007/s11440-024-02524-4","url":null,"abstract":"<div><p>Mobile sand dunes have been recognized as quite tricky natural disaster in Central and Western China. Consequently, proposing an effective and environmentally friendly method to combat mobile sand dunes is of great significance. In this study, a combined technology, enzyme-induced carbonate precipitation (EICP) and sand plants, is proposed to control the mobile sand dunes. Laboratory experiments and large-scale on-site tests were conducted to demonstrate the feasibility of this combined technology to improve the success rate for treating mobile sand dunes. The results showed that using a first spray solution before germination with concentrations of 0.05 mol/L (calcium source solution) and 10 g/L (urease solution), the sand plants (Alfalfa, Astragalus, and Sarcozygium) had an optimal germination rate. For the second spray solution after germination, it is recommended to employ a solution comprising 0.05 mol/L, 40 g/L at an application amount of 4 L/m² (spray amount), using a one-phase injection method to improve the spray efficiency, which had the highest strength, the best water retention, and the best erosion resistance. Therefore, wind erosion resistance during on-site test was significantly improved, and the desert sands in the Ulanbuh Desert were not affected by wind for 60 days or more. The results demonstrated that combined technology was effective in preventing mobile sand dune movement, which presents promising potential for wide application in desert area.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1921 - 1934"},"PeriodicalIF":5.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716686","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}

{"title":"Statistical damage constitutive model of MICP-treated specimens based on lognormal distribution","authors":"Qiwu Jiang,&nbsp;Ming Huang,&nbsp;Kai Xu,&nbsp;Mingjuan Cui,&nbsp;Shuang Li,&nbsp;Guixiao Jin","doi":"10.1007/s11440-024-02509-3","DOIUrl":"10.1007/s11440-024-02509-3","url":null,"abstract":"<div><p>Microbial-induced carbonate precipitation (MICP) technique has the potential to be an eco-friendly and sustainable solution for engineering problems. Despite the extensive amount of research that has been conducted recently on the MICP technique, there are few studies on the constitutive model of MICP-treated specimens. In this study, the statistical damage constitutive model of MICP-treated specimens was established based on the statistical theory and damage mechanics theory. The proposed model assumed that the microelement strength of biocemented sand follows the lognormal distribution and the Drucker–Prager criterion. The parameters <i>S</i>_<i>0</i> and <i>F</i>_<i>0</i> in the constitutive model were determined, and their physical significance was then discussed. The reasonableness of the proposed model was verified by comparing the theoretical results and the experimental results. The evolution of the damage variable (<i>D</i>), parameter <i>S</i>_<i>0,</i> and parameter <i>F</i>_<i>0</i> with different calcium carbonate content (<i>CCC</i>) was analyzed. The statistical damage model based on the lognormal distribution was then compared with that based on the Weibull distribution. The results show that the parameter <i>F</i>_<i>0</i> and <i>S</i>_<i>0</i> can reflect the limiting strength and brittleness of MICP-treated specimens.. The specimens with higher cementation tend to have a higher accelerated damage rate. The damage variables eventually reach a stable value as the axial deformation increases. The proposed model can reflect the strain softening and strain hardening phenomena well, which can also represent the shear expansion and shear contraction characteristics of the volume strain curve. Overall, the research in this study can provide some theoretical support for the engineering application of MICP-treated specimens.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1759 - 1775"},"PeriodicalIF":5.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716785","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}

{"title":"Field study on the shaft capacity of pre-bored grouted planted pile embedded in deep soft soil","authors":"Jia-jin Zhou,&nbsp;Ri-hong Zhang,&nbsp;Jian-lin Yu,&nbsp;Xiao-nan Gong,&nbsp;Wei Ming","doi":"10.1007/s11440-024-02522-6","DOIUrl":"10.1007/s11440-024-02522-6","url":null,"abstract":"<div><p>This paper presents a group of field tests to investigate the shaft capacity of pre-bored grouted planted (PGP) pile embedded in deep soft soil. Totally three test PGP piles were designed for the static load tests. The fiber optic sensors were equipped along the PHC pile shaft of two test piles to investigate the reliability and accuracy of fiber optic sensors on measuring the axial force of PGP pile. The diameter of cemented soil column of test PGP pile was 560 mm, and the diameter of core PHC pipe pile was 400 mm. The thickness of cemented soil layer around the PHC pipe pile reached 80 mm. The test results showed that: the base capacity of three test piles were all not fully mobilized when loaded to the designed ultimate capacity 3000 kN, and the base capacity of test pile TP1 and TP2 were 14.4% and 14.8%, respectively of the applied pile head load when loaded to 3000 kN. The skin friction of cemented soil–soil interface was fully mobilized when the pile–soil relative displacement reached 10 mm, 1.8% D (D is pile diameter). The measured ultimate skin friction of test pile TP1 and TP2 in different soil layers were 1.21–1.88 times of the recommended ultimate skin friction of bored pile, which can be used for the design of PGP pile in following engineering projects. The increase of cemented soil layer thickness (increase of pile diameter) could increase the entire shaft capacity of PGP pile, on the condition that the core PHC pile and cemented soil layer act as a unit in the load transfer process.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1935 - 1946"},"PeriodicalIF":5.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716643","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}

{"title":"Strength enhancement of Ca(OH)2 activated ground granulated blast furnace slag-stabilized dredged sediments using Na2CO3","authors":"Ning Ma,&nbsp;Hailong Ye,&nbsp;Clarence Edward Choi,&nbsp;Jiaqi Zhang","doi":"10.1007/s11440-024-02470-1","DOIUrl":"10.1007/s11440-024-02470-1","url":null,"abstract":"<div><p>The efficiency of alkali-activated ground granulated blast furnace slag in stabilizing dredged sediments with high water contents is suboptimal because the activators become diluted. To improve stabilization efficiency, additives such as nano-CaCO₃ are proposed. However, some of the proposed additives may not be practical owing to their high costs. This study experimentally investigates the addition of Na₂CO₃ for the stabilization of dredged sediment with high water contents (i.e., 100%) using Ca(OH)₂-activated slag. Experimental results show the optimal content of Na₂CO₃ to obtain the highest 28-day unconfined compressive strength of stabilized sediments is 0.2% gravimetrically. Below the optimal content, the strength increases with Na₂CO₃ content. Above the optimal content, a decrease in strength is observed. By examining the reaction products and microstructure of the stabilized dredged sediments, it is observed that the coupling mechanism of cation exchange and calcite precipitation promotes the development of finer capillary pores, leading to a reduction in interpore connectivity and lower structural heterogeneity of the fine capillary pores. Experimental evidence from this study broadens the practical applications of sustainable soil stabilization using additives.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"945 - 964"},"PeriodicalIF":5.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02470-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361684","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}

{"title":"Failure analysis of time-delayed collapse triggered by time-dependent fracturing in a deep TBM tunnel","authors":"Chen Fan,&nbsp;Xia-Ting Feng,&nbsp;Zhi-Bin Yao,&nbsp;Lian-Jie Fu,&nbsp;Meng-Fei Jiang,&nbsp;Cheng-Xiang Yang,&nbsp;Jun Zhao,&nbsp;Bin Lv,&nbsp;Jian-Shu Xu","doi":"10.1007/s11440-024-02506-6","DOIUrl":"10.1007/s11440-024-02506-6","url":null,"abstract":"<div><p>As the underground engineering advances into the deep, high geostress and complex geological conditions increasingly trigger various time-delayed failures. Recently, a new time-dependent surrounding rock failure, named time-delayed collapse, has been encountered multiple times during the construction of a deep TBM tunnel. This time-delayed failure started from the potential unstable rock mass cut by structural planes and was manifested as the heavy blocks detaching from the surrounding rock eventually due to continuous time-dependent fracturing. The examination of the evolution process indicates that intersecting structural planes in the surrounding rock are critical prerequisites for time-delayed collapse. After excavation, under high geostress and gravity, continuous time-dependent fracturing serves as the intrinsic driver of failure development, leading to significant spatial–temporal lag characteristics. Field monitoring also showed that different geological conditions would result in distinct fracturing characteristics during development. However, compared to rockbursts, the subtle time-dependent deformation or weak microseismic activities in time-delayed collapse areas pose challenges for in prediction or prevention in field monitoring.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1455 - 1470"},"PeriodicalIF":5.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570928","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}