Underground Space最新文献

{"title":"Experimental study on mix proportion optimization of anti-calcium dissolution shotcrete for tunnels based on response surface methodology","authors":"Chongming Tian ,&nbsp;Yueping Tong ,&nbsp;Junyuan Zhang ,&nbsp;Fei Ye ,&nbsp;Guifeng Song ,&nbsp;Yin Jiang ,&nbsp;Meng Zhao","doi":"10.1016/j.undsp.2023.07.002","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.07.002","url":null,"abstract":"<div><p>Aiming at the issue of crystallization and blockage of drainage system due to the massive calcium loss from the tunnel shotcrete, a self-designed tunnel seepage crystallization modelling system was developed. This system was produced in conjunction with the initial tunnel support shotcrete construction and drainage pipe installation, and is capable of simulating both the seepage process of groundwater in the shotcrete and the process of crystallization in the drainage pipe. Based on three different mechanisms of anti-crystallization, which include absorbing free calcium, reducing the porosity and increasing hydrophobicity, antialkali agent, nano-calcium carbonate, and silane were selected to test, respectively. Firstly, the suitable dosing ranges of these three external admixtures for resisting calcium loss in shotcrete were determined by single factor tests, which were 7%–11%, 4%–8%, and 0.3%–0.5%, respectively. Thereafter, the response surface method was employed to evaluate the interaction of antialkali agent, nano-calcium carbonate and silane on calcium loss in shotcrete, and to establish the relationship between them, and thus to determine the admixture ratio that can effectively reduce calcium loss crystallization in shotcrete, with the optimal admixture amounts of antialkali agent being 9.242%, nano-calcium carbonate 4.889% and silane 0.366%. Lastly, the reliability of the model test results was verified by the microscopic analysis, and the results showed that the total amount of calcium dissolution in the optimized group could be reduced by 75% compared with the blank control group, and was basically consistent with that derived from the response surface regression model, validating the high accuracy of the buildup response surface regression model. The present study can provide some ideas and references for reducing the seepage crystallization behavior of groundwater in the initial tunnel support shotcrete.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967423001290/pdfft?md5=19e26bfa187e0b1c2cf364e4ea269387&pid=1-s2.0-S2467967423001290-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92059499","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":"Experimental study on performance of spring damping support structure system for large deformation tunnel in soft rock","authors":"Jinfeng Xu ,&nbsp;Xiongyao Xie ,&nbsp;Zhou Shi ,&nbsp;Wuqiang Cai ,&nbsp;Dinglun Xu ,&nbsp;Chen Xu","doi":"10.1016/j.undsp.2023.08.012","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.08.012","url":null,"abstract":"<div><p>According to the convergence confinement theory, it is an effective measure to control the large deformation of high ground stress in fractured soft rock tunnels by using yielding support. The yielding support can be classified as either radial or circumferential yielding support. Circumferential yielding support is achieved by transforming radial displacement into circumferential tangential closure without compromising the support capacity of the primary lining support structure. Based on this, and inspired by the design principle of dampers, a yielding support structure system with spring damping elements as its core was developed, based on the connection characteristics of steel arches in highway tunnel, which can provide increasing support resistance in the yielding deformation section. Then the mechanical properties of spring damping elements were obtained through indoor axial pressure and flexural tests. In addition, according to these results with numerical calculations, the yielding support structure system with embedded spring damping elements can reduce the internal force of the support structure by approximately 10% and increase the area of the plastic zone of the surrounding rock by 11.23%, which can fully utilize the self-bearing capacity of surrounding rock and verify the effectiveness of circumferential yielding support. Finally, the spring damping support structure system was designed with reference to the construction process of the tunnel excavated by drilling and blasting method, and the transformation of the spring damping element to spring damping support structure was achieved. Based on field test results, surrounding ground pressure for the yielding support optimization scheme was reduced by 40% and more evenly distributed, resulting in the successful application and a reduction in the construction cost of large deformation tunnels in soft rock.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967423001307/pdfft?md5=22ca62e737a773d322985d2dd51875b8&pid=1-s2.0-S2467967423001307-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92059500","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":"Effect of seepage on soil arching effect in deep shield tunnel","authors":"Xu Song,&nbsp;Fan-Yan Meng,&nbsp;Ren-Peng Chen,&nbsp;Han-Lin Wang,&nbsp;Huai-Na Wu","doi":"10.1016/j.undsp.2023.02.011","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.02.011","url":null,"abstract":"<div><p>Shield tunneling and post-tunneling steady seepage are accompanied by stress and displacement variations, which could induce and influence the soil arching effect. Although there are many studies on the tunneling-induced soil arching effect, the research about the effect of seepage on soil arching effect is extremely lacking. In this study, a numerical model is firstly established and verified by field data. Then, a series of numerical models, whose simulation method of steady seepage is verified by adopting the conformal mapping technique, are established to study the soil arching evolution of deep-buried tunneling and post-construction steady seepage. The results indicate that seepage leads to an increase in effective vertical stress, which is consistent with the existing theory. The seepage weakens the soil arching effect resulting in the height of the arch zone reducing from 2.38<em>D</em> (<em>D</em> is the tunnel diameter) to 1.25<em>D</em>. The seepage leads to the further development of ground consolidation settlement, but the differential displacement in the soil mass decreases. The ground reaction curve in the steady seepage condition shows a bigger value than that after excavation. It is reasonable to control the ground loss ratio in the range of 0.5–1.0%, which can minimize overburden pressure with moderate ground deformation.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715119","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":"Performance-based three-level fortification goal and its application in anti-dislocation countermeasures: A case study of Shantou Submarine tunnel","authors":"Tianqiang Wang,&nbsp;Ping Geng,&nbsp;Guoguo Liu,&nbsp;Changjian Chen,&nbsp;Wenqi Gu","doi":"10.1016/j.undsp.2023.02.013","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.02.013","url":null,"abstract":"<div><p>The dislocation momentum is the design basis for anti-dislocation to tunnel when a tunnel crosses an active fault. The influence of different dislocation levels on tunnel performances is not clear. Thus, based on seismic activity parameters at the site of interest and probability of fault dislocation, probability fault displacement hazard analysis (PFDHA) methodology was introduced in this paper to ascertain the fault dislocation level under different exceeding probabilities (63%, 10%, and 2%–3%). Then, based on the definition of different ground motion strength and fortification goals of the tunnel, a three-level fortification goal with different performance requirements of the tunnel was proposed. The first attempt to use the proposed indexes including the maximum dislocation of the tunnel and maximum relative deformation of the tunnel was tried to evaluate deformation and failure states with an experimental approach. Subsequently, the feasibility of the three-level fortification goal was further investigated according to the self-defined qualitative description and quantitative indexes in the segmental design and sectional expansion tunnels comprehensively. The results show that the fault dislocations relying on PFDHA at the site of the Shantou Submarine Tunnel are firstly ascertained as 0.04, 1.8, and 2.4 m respectively. Taking the fault dislocation as model input values into account, the dislocation mechanism of the tunnel under the three levels was revealed. More importantly, judging from the dislocation performance requirements of the three-level fortification goal, the tunnel deformation and failure states are mitigated by adopting the countermeasures. The sectional expansion design can well meet the requirements without the restriction of a strong earthquake, while the effectiveness of the segmental tunnel can be proved under frequently occurred and fortification earthquake. The final research results are expected to provide a new fortification goal for anti-dislocation hazard evaluation on expansion design in high-intensity seismic regions and segmental design in slight and moderate-intensity seismic regions.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715124","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":"Uncovering the relationship among spatial vitality, perception, and environment of urban underground space in the metro zone","authors":"Yajie Xu ,&nbsp;Xiangsheng Chen","doi":"10.1016/j.undsp.2023.02.010","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.02.010","url":null,"abstract":"<div><p>With the rapid development of rail transit, effectively developing urban underground space (UUS) in the metro zone has become an important approach to expanding urban space. However, UUS is currently facing problems, such as an uneven distribution or even loss of vitality, which restricts the utilization efficiency of the space. Thus, we established a UUS environmental assessment system based on the “comfort-aesthetic-function-traffic-structure” using space syntax, instrumental measurement, and questionnaire surveys. By constructing a partial-least-square structural equation model, the internal relationships between the UUS environment and corresponding space vitality and space perception under different study areas, namely the underground transportation-oriented space (transportation space for short) and the underground commercial-oriented space (commercial space for short), were studied in detail throughout the working day. Results indicate the following: (1) the UUS in the metro zone environment influences spatial vitality. The vitality distribution of transportation space is significantly affected by the spatial traffic and structure. The vitality distribution of commercial space is significantly affected by the spatial function and traffic. (2) The environment of UUSs in the metro zone influences users's perception. The perception of transportation space is significantly affected by aesthetics and comfort. The perception of commercial space is significantly affected by aesthetic, comfort, and spatial functions. (3) The user's perception affects vitality, and the effect is more significant in commercial space. This study provides an in-depth understanding of the relationship between the complex environment and its spatial vitality as well as the spatial perception of the UUS in metro zones. Our research results provide a novel approach and theoretical basis for the development and application of UUS vitality in various cities.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715186","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":"Numerical investigation of tunneling induced surface movement: A case study of MRT line 1, Dhaka","authors":"Khondaker Sakil Ahmed ,&nbsp;Johana Sharmin ,&nbsp;Mehedi Ahmed Ansary","doi":"10.1016/j.undsp.2023.02.008","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.02.008","url":null,"abstract":"<div><p>The proposed underground tunnel for Mass Rapid Transit Line 1, Dhaka brings immense attention to the engineers and experts not only because of its construction challenges through a densely-built city, but also for the potential tunneling-induced ground settlements. This very preliminary study investigates the ground surface movement due to the progression of the tunnel boring machine (TBM) using numerical analysis. A series of finite element (FE) models have been developed using PLAXIS 3D, in which Mohr–Coulomb (MC), modified Cam-Clay (MCC), and hardening soil (HS) have been considered. The in-field data of Mashhad Metro Line-2 have been compared to verify PLAXIS 3D's efficacy in tunnel modeling. Subsequently, the outcomes of the FE analyses are compared with the existing empirical formulas. The PLAXIS 3D analysis considering the MCC soil model exhibits strong agreement with the real monitored data, with a variance of only 3.85%. After simulating different stages of the tunnel construction, results are reported in terms of the distance of the inflexion point from the center, the settlement trough pattern, the maximum transverse settlements, and the vertical settlements. They are also compared with the established empirical formula. In order to comprehend the surface settlement with various tunnel depths and diameters, a parameter dependency study has been carried out. The analysis findings showed that increasing the TBM’s depth and radius causes the inflexion point’s distance from the center of the tunnel to increase by 4% and decrease by 5%, respectively. It is also observed that as tunnel depth increases, the overall settlement of the tunnel lowers by 11% for every additional 5 meters of depth. The MCC model, out of the three, exhibits the most accurate value of the settlement compared to that obtained from the empirical solutions, and also the best-fit form to the Gaussian curve.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715159","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":"Flexural stiffness characterization of the corrugated steel–concrete composite structure for tunnel projects","authors":"Wenqi Ding ,&nbsp;Xuanbo Huang ,&nbsp;Shuobiao Li ,&nbsp;Wentong Liu ,&nbsp;Qingzhao Zhang","doi":"10.1016/j.undsp.2023.02.003","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.02.003","url":null,"abstract":"<div><p>Corrugated steel–concrete (CSC) composite structures are increasingly used in tunnel and culvert projects due to their good mechanical properties. The design of CSC composite structures is often governed by deflection limits in service, hence it becomes crucial to evaluate accurately their flexural stiffness. In this work, the deflection deformation mechanism of CSC composite structure is studied by experimental and numerical methods, and a simplified formula for calculating the flexural stiffness is established. In addition, the deflection results obtained by different methods are compared and analyzed. It is found that: (1) the flexural stiffness of the CSC composite structure is constant only when the load is small, and after the bending moment exceeds a certain value, the flexural stiffness will gradually become smaller as the bending moment increases. (2) The value of the bending moment corresponding to the end of the elastic stage of the bending moment-deflection curve increases with the increase of the axial force in the composite structure. (3) As the axial force of the composite structure increases, the flexural bearing capacity of the structure increases first and then decreases.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715043","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":"Influence of extreme shallow jacked box tunnelling on underlying metro tunnels: A case study","authors":"Xiaobing Xu ,&nbsp;Lei Tong ,&nbsp;Zhuofeng Li ,&nbsp;Xingwang Liu ,&nbsp;Qi Hu ,&nbsp;Hongbo Yao ,&nbsp;Junyi Li","doi":"10.1016/j.undsp.2023.04.001","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.04.001","url":null,"abstract":"<div><p>The application of jacked box tunnelling for underground passages has grown rapidly in recent years in China. In this study, the design of an extreme shallow jacked box tunnel traversing the underlying metro tunnels was introduced. An innovative additional soil filling above the ground surface was carried out to overcome the overlying-soil-carrying effect of the extreme shallow jacked box tunnelling. The structural safety of metro tunnels during the jacking process was analyzed through in-situ monitoring. It indicated that the overlying-soil-carrying effect was successfully alleviated. The metro tunnels generally showed horizontal displacement towards the receiving shaft, uplift and horizontal stretch during the jacking process. The stop of jacking machine in front of obstacles generally contributed to the decrease of horizontal displacement, uplift and horizontal stretch of metro tunnels. The largest horizontal displacement (1.3–1.6 mm), uplift (1.5 mm) and horizontal convergence (1.6–1.8 mm) generally occurred when the reception of jacking machine was completed, and they all met the requirement of 2 mm for this project. The design and construction of this shallow jacked box tunnel project could provide references for future similar projects.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715122","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":"Seismic analysis of underground tunnels subjected to 3D oblique incident P and SV waves by 2.5D approach","authors":"Yeong-Bin Yang ,&nbsp;Xiaoli Wang ,&nbsp;Zeyang Zhou ,&nbsp;Xiongfei Zhang ,&nbsp;Zhi Li","doi":"10.1016/j.undsp.2023.03.004","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.03.004","url":null,"abstract":"<div><p>This paper presents, for the first time, the consideration of three-dimensional (3D) oblique incident P and SV waves in calculating the 3D seismic response of a lined tunnel embedded in a half-space by the 2.5D finite/infinite element method (FIEM). Firstly, the applicability of the 2.5D FIEM for 3D seismic analysis is summarized. With the exact solutions obtained for the free field in the Appendix, the equivalent seismic forces are rationally computed for the near-field boundary, considering the horizontal and vertical excitations of the Chi-Chi Earthquake. By performing seismic analysis of the half space embedded with a tunnel using the 2.5D FIEM, the time-domain responses of the tunnel are obtained. The accuracy of the present solutions is verified against those of de Barros and Luco. Conclusions drawn from the parametric study include: (1) Stress concentration for the principal stress under oblique incident seismic waves occurs at the polar angles of <span><math><msup><mn>0</mn><mo>°</mo></msup></math></span> (vault), <span><math><msup><mn>90</mn><mo>°</mo></msup></math></span>, <span><math><msup><mn>180</mn><mo>°</mo></msup></math></span> (inverted arch), and <span><math><msup><mn>270</mn><mo>°</mo></msup></math></span> of the lining wall. (2) The vault and inverted arch are the weakest parts of the tunnel during earthquakes. (3) The accelerations of the tunnel during earthquakes can be regarded as of the rigid body type. (4) The responses of the tunnel lining caused by SV waves of an earthquake are much more critical than those by P waves. (5) For arbitrary seismic waves, the maximum longitudinal acceleration <span><math><msub><mi>a</mi><mrow><mi>z</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> is of the same order of magnitude as the maximum horizontal acceleration <span><math><msub><mi>a</mi><mrow><mi>x</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span>.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715125","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":"Review of constraints and critical success factors of developing urban underground space","authors":"Yani Lai ,&nbsp;Yuling Wang ,&nbsp;Jing Cheng ,&nbsp;Xiangsheng Chen ,&nbsp;Quan Liu","doi":"10.1016/j.undsp.2023.03.001","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.03.001","url":null,"abstract":"<div><p>The development of urban underground space (UUS) is of great significance for sustainable urban development because it has potential to solve many urban problems. However, the development of UUS is limited because there are still a lot of constraints and challenges. To better understand the constraining factors of developing UUS and improve the development and utilization of UUS, this study conducts a comprehensive survey of existing literature retrieved from the Web of Science Core Collection database. Five main constraining factors, including the limited geological conditions, high cost, lack of natural light and ventilation, high incidence, and difficulty in collecting data and information on UUS, have been discussed to better understand how they affect the development of UUS. Based on the survey, the critical success factors of developing UUS, such as the effective governance structure, planning system for integrating UUS into urban development, coordination of the design of ground and underground, delineation of land property rights of UUS, and application of information techniques in the use of UUS, have been identified and discussed. In addition, knowledge gaps in the studies on development of UUS have been identified. Finally, the research trends and future directions have been proposed for better understanding and practice of UUS development.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":null,"pages":null},"PeriodicalIF":6.4,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49715162","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}