Engineering Structures最新文献

{"title":"Self-centering tension brace for seismic damage mitigation: From real-time hybrid simulation test to performance-based seismic retrofit design","authors":"Jishuai Wang ,&nbsp;Tong Guo ,&nbsp;Yazhou Xie ,&nbsp;Yunwen Zhang","doi":"10.1016/j.engstruct.2025.120135","DOIUrl":"10.1016/j.engstruct.2025.120135","url":null,"abstract":"<div><div>Various self-centering tension braces (SCTBs) have been proposed to enhance the seismic resilience of existing buildings. However, studies validating their seismic retrofit efficacy under dynamic seismic excitations remain limited, and performance-based retrofit design methodologies using SCTBs are still absent, hindering their practical applications in earthquake engineering. This paper first conducts a real-time hybrid simulation test on a reinforced concrete (RC) frame installed with two SCTB specimens to verify the SCTBs’ retrofit efficacy. Subsequently, a multi-step performance-based seismic retrofit method is proposed, utilizing SCTBs to retrofit two RC frames with varying numbers of stories and retrofit objectives. Finally, seismic fragility assessment using Latin hypercube sampling and incremental dynamic analysis are conducted for the retrofitted frames, considering uncertainties in both structural attributes and ground motion inputs. The real-time hybrid simulation test demonstrates that SCTB has excellent retrofit efficacy under seismic excitations, with 17 % and 84 % reductions in the mean values of the maximum and residual story drifts, respectively. Also, both the deterministic analyses and fragility assessment demonstrate that the proposed performance-based seismic retrofit design method achieves the preassigned performance objectives without the need for repeated iterations. The retrofitted structures exhibit needed resilience against structural collapse under maximum considered earthquakes and prompt post-earthquake recovery under design basis earthquakes.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120135"},"PeriodicalIF":5.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642568","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":"Effect of residual strains in damaged RC beam after unloading on the flexural and shear behaviours of SSS-ECC repaired beams","authors":"Dapeng Zhao,&nbsp;Shaohua Wang,&nbsp;Ke Li,&nbsp;Jiajun Fan,&nbsp;Xiaoxiao Zhou,&nbsp;Yong Liang","doi":"10.1016/j.engstruct.2025.120144","DOIUrl":"10.1016/j.engstruct.2025.120144","url":null,"abstract":"<div><div>This study investigated the effect of residual strains in damaged reinforced concrete (RC) beam after unloading on the flexural and shear behaviours of these beams repaired using stainless-steel strand reinforced engineered cementitious composites (SSS-ECC). Seventeen RC beams, including three controls and fourteen repaired beams, were pre-damaged, repaired using SSS-ECC, and underwent secondary loading. The test variables included the damage levels, reinforcement ratios of SSS, shear span-to-effective depth ratios, and repair methods. The test results demonstrated that SSS-ECC exhibited multiple cracking behaviour, thereby enhancing energy dissipation and delaying failure of the repaired beams. Compared to the control beams, the ultimate loads of the flexural-repaired and shear-repaired beams increased by 43 %-68 % and 23 %-48 %, and the ultimate deflections increased by 8 %-43 % and 25 %-83 %, respectively. The residual strains in RC beams after unloading increased exponentially with the damage levels, and the presence of residual strains resulted the performance degradation of the repaired beams. Increasing the reinforcement ratio of SSS enhanced improvements of strength and deformation. Increasing the shear span-to-effective depth ratio reduced the strength improvement but had a minimal effect on the deformation improvement. The U-wrapped method was less efficient than the fully-wrapped and both-sided bonding methods. Furthermore, a residual strain calculation model and a novel method for predicting flexural and shear strengths considering residual strains were proposed. Compared to existing models, the proposed model showed good accuracy and applicability, providing a new strategy for understanding the effect of residual strains and repair design.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120144"},"PeriodicalIF":5.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642570","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 hybrid forcasting model of temperature gradient in longitudinal slab tracks on bridge-subgrade transition zones","authors":"Feng Li ,&nbsp;YiYao Zhang ,&nbsp;Rui Zhou ,&nbsp;Qingsong Feng ,&nbsp;Zaiwei Li ,&nbsp;Guowen Yao ,&nbsp;Lihai Zhang","doi":"10.1016/j.engstruct.2025.120053","DOIUrl":"10.1016/j.engstruct.2025.120053","url":null,"abstract":"<div><div>A hybrid particle swarm optimization and support vector machine (PSO-SVM) model was proposed to accurately forecast the temperature gradients in longitudinal slab ballastless tracks on a bridge and subgrade transition zone in this paper. Based on the monitoring experiment in climate extremes, the characteristics of meteorological factors and internal temperature were analyzed. Subsequently, the nonlinear correlations of meteorological factors and temperatures gradient on three different foundations were analyzed by five copula functions. Moreover, two theoretical temperature gradients’ thresholds were deduced, the SVM and PSO-SVM model were then established to forecast the temperature gradients, respectively. Results show that the track slab on transition zone has the largest temperature gradient among three foundations. The Frank copula function has the best effect in reflecting the joint distribution between meteorological factors and temperatures gradient. Moreover, the forecasting effect based on the displacement threshold requirement is better than that the axial force threshold requirement. The PSO-SVM model with the Radial Basis Function kernel has the best forecasting effect with the accuracy greater than 93 %.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120053"},"PeriodicalIF":5.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642572","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":"Progressive collapse resistance of prestressed precast concrete substructures with slot-bolted top-seat angles","authors":"Hai-Rong Shi ,&nbsp;Bin Zeng ,&nbsp;Kai Qian ,&nbsp;Chun-Lin Wang","doi":"10.1016/j.engstruct.2025.120134","DOIUrl":"10.1016/j.engstruct.2025.120134","url":null,"abstract":"<div><div>Prestressed precast concrete frames rely on post-tensioned strands and energy dissipaters to interconnect members, but their progressive collapse resistance is often limited by the low deformation capacity of the dissipaters. This study introduced a novel top-seat angle connection with slotted bolt holes that enabled controlled slippage under large deformations, delaying premature failure. A comprehensive mechanical model was first developed to characterize the full-range force-deformation behavior of slot-bolted angles. Four frame substructures were then tested under a column removal scenario: one monolithic concrete specimen and three precast concrete specimens—one without angles, one with column-leg-slotted angles, and one with double-slotted angles. Results demonstrated that the precast specimen without angles outperformed the monolithic specimen under catenary action (CA) but showed weaker compression arch action (CAA). Incorporating slotted angles significantly improved CAA stiffness and resistance, achieving performance comparable to monolithic construction. Notably, the slotted angles provided a deformation capacity twice that of conventional designs and contributed approximately 20 % of total resistance at the ultimate state of collapse. The double-slotted angles could further enhance the load-bearing capacity of the substructure over the column-leg-slotted angles. These findings validated the effectiveness of slot-bolted top-seat angles in enhancing progressive collapse resistance of prestressed precast concrete frames.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120134"},"PeriodicalIF":5.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642573","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 data-driven approach for predicting peak floor response based on visually observed rocking behaviors of freestanding NSCs","authors":"Yongqing Jiang ,&nbsp;Jianze Wang ,&nbsp;Weiwei Chen ,&nbsp;Kaoshan Dai","doi":"10.1016/j.engstruct.2025.120006","DOIUrl":"10.1016/j.engstruct.2025.120006","url":null,"abstract":"<div><div>Accurate prediction of structural responses under earthquakes is crucial for seismic performance evaluation. Traditional methods of obtaining structural response mainly rely on costly structural health monitoring (SHM) systems while paying little attention to the damage state of unanchored non-structural components (NSCs). The surveillance system is commonly equipped in commercial and public buildings, which could be used to capture the response motions and damage states of NSCs during earthquakes. To this end, this study aims to develop a method for inferring peak floor acceleration (PFA) based on the observed seismic response of NSCs. Three computer vision tasks for collecting responses of NSCs with different data ambiguity are considered. For a purpose of the method implementation, three prototype structures with different heights are used in this study. Freestanding NSCs with different geometric properties are considered to be placed in the structures. Under a synthesis of ground motions, the datasets for floor acceleration responses of the structures and dynamic responses of freestanding NSCs are obtained via numerical simulations. This study finds out that regression models for predicting PFA values are untrustworthy due to the weak correlation between PFAs and response quantities of NSCs. Instead of predicting exact PFA values, the potential PFA ranges are considered to be predicted and a list of PFA ranges is determined based on rocking fragility models of freestanding NSCs. Machine learning techniques are employed to build the surrogate models and the results demonstrate the accuracy and interpretability of the PFA range prediction with the <span><math><mrow><mrow><mrow><mi>F</mi></mrow><mrow><mn>1</mn></mrow></mrow><mo>‐</mo><mi>s</mi><mi>c</mi><mi>o</mi><mi>r</mi><mi>e</mi></mrow></math></span> ranging from 84 % to 94 %.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120006"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632137","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":"Crack width simulation with discrete reinforcement and 3D nonlinear finite element models","authors":"Christina Krenn,&nbsp;Dirk Schlicke","doi":"10.1016/j.engstruct.2025.120122","DOIUrl":"10.1016/j.engstruct.2025.120122","url":null,"abstract":"<div><div>Crack control is essential for the serviceability and durability of reinforced concrete structures. Until today a variety of crack width calculation models have been proposed, but there is still no generally agreed method provided in standards or literature. Overall, the existing models have different influencing parameters and even the relationship between experimentally measured, numerically simulated and analytically calculated crack widths is not clearly understood. Furthermore, the distinction between crack width at the reinforcement level and at the surface is controversially presented in the literature. This paper presents a detailed numerical finite element volume model for the simulation of crack opening in reinforced concrete that considers reinforcement ribs discretely. This aims to represent the complex stress state in the concrete near the ribs including the internal cracks. A parametric study is performed to determine the main factors influencing the crack width. Comparisons with experimental results show that the model realistically captures the crack width over the depth of the concrete cover. Additionally, comparisons with analytically calculated crack widths indicate that the analytical method based on displaceable bond primarily predicts the surface crack width. The difference between the crack width at the reinforcement level and at the surface is predominantly attributed to internal cracking whereas shear-lag deformations of the concrete itself are insignificant. The study also highlights the importance of distinguishing between the single crack and stabilized crack stages in crack width calculations and emphasizes the need to consider slip-dependent bond stress in analytical models.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120122"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632139","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":"Seismic experimental research on damaged resilient reinforced concrete columns retrofitted by FRP sheets","authors":"Yunjian He ,&nbsp;Gaochuang Cai ,&nbsp;Cheng Xie ,&nbsp;Prafulla Bahadur Malla ,&nbsp;Yiyuan Li ,&nbsp;Amir Si Larbi","doi":"10.1016/j.engstruct.2025.120119","DOIUrl":"10.1016/j.engstruct.2025.120119","url":null,"abstract":"<div><div>The post-earthquake repairability was an attractive advantage of reinforced concrete (RC) frame structures with resilient RC (RRC) members. This paper investigates the seismic behavior of six RRC columns repaired with different fiber-reinforced polymer (FRP) types, the number of FRP layers, and additional steel plates. The results indicate that all original RRC columns exhibited a drift-hardening behavior before the drift ratio reached 3.0 %, while the residual drift ratio was less than 0.5 %. FRP-repaired RRC columns can achieve even higher peak strength than the original columns and effectively control their residual deformation. The increase in the number of carbon FRP (CFRP) layers leads to a decrease in residual displacement, while the type of FRP has no significant effect. Compared with the Aramid FRP-repaired column, the CFRP-repaired column showed higher initial stiffness and lower stiffness degradation rate. The FRP-steel plate repaired columns showed the highest initial stiffness and energy dissipation capacity. A simplified model containing two yield points was proposed to evaluate the residual displacement of the repaired RRC column referring to the FEMA’s recommendation which was based on the displacement at steel bar yield. In addition, a bilinear skeleton model curve based on a simplified hysteresis loop rule was proposed to predict the hysteresis behavior of the repaired RRC columns.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120119"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632140","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":"Machine learning-based and interpretable models for predicting the resistance and probability of progressive collapse of steel frame-composite floor structures","authors":"Yuxu Guo ,&nbsp;Bo Yang ,&nbsp;Shagea Alqawzai ,&nbsp;Kang Chen ,&nbsp;Deyang Kong","doi":"10.1016/j.engstruct.2025.120089","DOIUrl":"10.1016/j.engstruct.2025.120089","url":null,"abstract":"<div><div>Steel frame-composite floor (SF-CF) structures are particularly susceptible to progressive collapse due to their complex load distribution and potential vulnerabilities at critical joints, making them a high-risk system in the event of localized failure. This study aims to investigate the methods for predicting and analyzing the progressive collapse behavior of SF-CF structures. A theoretical and predictive model was developed based on the Minimal Substructure Mechanics Model and the Collapse Probability Prediction Method Based on the Randomness of Structural Load (CPPM-RSL). Machine learning (ML) techniques from artificial intelligence (AI) were employed to predict and analyze the progressive collapse behavior probabilistically. Initially, a dataset comprising various scenarios of column failure was established. The performance of five typical ML models was assessed and compared based on this dataset, focusing on the robustness and generalization capability. Results revealed that the XGBoost model demonstrated inferior performance compared to the other four models, particularly regarding generalization capability. More refined hyperparameter optimization was performed to attempt to improve the performance of the XGBoost model. Grid search was employed to obtain the optimum hyperparameter configuration. K-Fold cross-validation was employed to further examine the generalization capability of the model under the optimal hyperparameter configuration. Additionally, reducing model complexity by decreasing the number of features was also attempted in response to the overfitting observed in the XGBoost model. The results indicated that these approaches did not significantly enhance the performance of the XGBoost model. Moreover, interpretable models based on the Shapley Additive exPlanations (SHAP) method and five ML models were developed. The importance of features in predicting structural collapse and their impact mechanisms were elucidated, providing recommendations to boost the structural resistance to collapse. It was also indicated that the employment of weak learners in XGBoost yields predictive values less than true values despite the obtained values being raised as much as possible in the SHAP values of the XGBoost model. Optimizing the structural geometric characteristics proved to be more effective than improving the properties of material in increasing the collapse resistance of structures. In conclusion, this study attempts to apply ML methods for predicting structural collapse behavior and provides a potential approach for predicting progressive collapse.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120089"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632141","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":"Vibration source characteristics and vibration reduction mechanism of the novel rubber pad floating slab track in metro turnout areas","authors":"Chuanqing Dai ,&nbsp;Tao Xin ,&nbsp;Sen Wang ,&nbsp;Yi Yang ,&nbsp;Chao Kong","doi":"10.1016/j.engstruct.2025.120107","DOIUrl":"10.1016/j.engstruct.2025.120107","url":null,"abstract":"<div><div>The vibration issues induced by metro turnout areas have become increasingly prominent recently. The novel rubber pad floating slab track (RPFST) is a type of assembled vibration-reducing track with the feature of slab-pad composite structure. To investigate the vibration source characteristics and the mechanism of vibration energy attenuation among different structural layers of the novel RPFST when a metro train passes through the turnout area, a vehicle-turnout-tunnel rigid-flexible coupled dynamic model was established based on the finite element method. It not only reflects the unique wheel-rail contact relationships in turnout area but also represents the vibration transmission of the nonlinear structural components of the turnout. Results show that, compared to the ordinary monolithic track bed (OMTB), the vibration source in the turnout area equipped with the novel RPFST exhibits narrower frequency band distribution, lower vibration amplitude, and longer vibration attenuation time. The novel RPFST can reduce the dominant frequency of tunnel wall vibrations. The dominant frequency in the crossing panel is higher than in other sections. The vertical and lateral vibration spectra of the tunnel wall both exhibit the characteristic of two frequency peaks, with the vertical vibration amplitude being about 1.3 times that of the lateral direction. The novel RPFST significantly attenuates the mid-to-low frequency vibration energy above 25 Hz in the turnout area, reducing energy by around 80 % after passing through the rubber pad layer, with a transmission loss can reach 23 dB. Compared to the OMTB, the insertion loss of the novel RPFST in the switch panel, closure panel, and crossing panel is 8 dB, 13 dB, and 9 dB, respectively.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120107"},"PeriodicalIF":5.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632138","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":"Quasi-static testing of rocking piers for railway bridges","authors":"Leixin Nie ,&nbsp;Lizhong Jiang ,&nbsp;Wangbao Zhou ,&nbsp;Zhiyong Jiang ,&nbsp;Yulin Feng ,&nbsp;Zhipeng Lai","doi":"10.1016/j.engstruct.2025.120110","DOIUrl":"10.1016/j.engstruct.2025.120110","url":null,"abstract":"<div><div>Rocking piers are increasingly recognized as a viable seismic isolation strategy for bridges. Compared to highway bridges, railway bridges are subjected to more stringent requirements for post-seismic functional recovery due to the elevated operational standards of train travel. Conventional rocking piers, however, encounter significant challenges. This study presents a rocking pier system specifically designed for railway bridges, with its feasibility confirmed through quasi-static testing. The test results demonstrate that incorporating rocking resilient hinges (RRHs) at the rocking interface enhances the rotational stability of the piers. The RRHs and horizontal limiting devices provide the pier with a nearly constant center of rotation during the rocking phase. This configuration effectively mitigates the inaccuracies typically associated with predicting the compressed area height of conventional rocking interfaces, significantly enhancing the predictive accuracy of the piers' behavior during and after earthquakes. An enlarged steel plate mounted on the top surface of the RRH assists in stress distribution, effectively preventing localized concrete damage and reducing repair costs following seismic events. In addition, the system's replaceable external energy dissipation devices facilitate rapid post-earthquake recovery. By embedding continuous unbonded prestressed tendons within the pier and coordinating with an enlarged base, the rocking interface remains closed under normal operational conditions or during frequent earthquakes, ensuring uninterrupted train functionality. The system's 'locking' mechanism is a final safeguard, fulfilling critical life safety objectives.</div></div>","PeriodicalId":11763,"journal":{"name":"Engineering Structures","volume":"332 ","pages":"Article 120110"},"PeriodicalIF":5.6,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629003","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}