Sanjay Prasad, Abhishek Mondal, Narayan Roy, R. Sahu
Liquefaction susceptibility of river channel deposit in Kolkata city is studied using laboratory cyclic triaxial tests. River channel deposit, which supports a large part of rapidly growing urbanization of Kolkata city, mainly consists of sandy soil with little amount of silt. Cyclic triaxial tests have been performed on this soil sample with varying relative density, confining pressure, and cyclic strain amplitude. Results are presented to show how these parameters influence the pore water pressure generation within soil. Relative density, confining pressure and cyclic strain amplitude are found to affect the pore pressure generation characteristics in the soil, and the number of cycles required to reach liquefaction phenomena vary significantly. Finally, pore pressure generation characteristics are modeled using a hyperbolic model and a pore pressure generation equation is proposed for the typical river channel deposit soil. The model exhibits a certain threshold value of cyclic strain amplitude, up to which the initial rate of pore pressure generation decreases and then increases.
{"title":"Liquefaction Behavior of Typical River Channel Deposit in Kolkata City","authors":"Sanjay Prasad, Abhishek Mondal, Narayan Roy, R. Sahu","doi":"10.4018/ijgee.329249","DOIUrl":"https://doi.org/10.4018/ijgee.329249","url":null,"abstract":"Liquefaction susceptibility of river channel deposit in Kolkata city is studied using laboratory cyclic triaxial tests. River channel deposit, which supports a large part of rapidly growing urbanization of Kolkata city, mainly consists of sandy soil with little amount of silt. Cyclic triaxial tests have been performed on this soil sample with varying relative density, confining pressure, and cyclic strain amplitude. Results are presented to show how these parameters influence the pore water pressure generation within soil. Relative density, confining pressure and cyclic strain amplitude are found to affect the pore pressure generation characteristics in the soil, and the number of cycles required to reach liquefaction phenomena vary significantly. Finally, pore pressure generation characteristics are modeled using a hyperbolic model and a pore pressure generation equation is proposed for the typical river channel deposit soil. The model exhibits a certain threshold value of cyclic strain amplitude, up to which the initial rate of pore pressure generation decreases and then increases.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84381161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On a Winkler foundation, solid circular plate vibration is examined using a higher-order finite element in polar co-ordinate system. The present formulation has developed a Mat-lab code to handle any boundary conditions. Validation of the code is carried out after the convergence studies. The results are compared to other researchers and show excellent conformity. Furthermore, a parametric analysis gave the first 10 natural frequency characteristics in tabular and graphical form. The authors conclude that the present formulation is straightforward, behaves exceptionally well for thin solid circular plates on elastic foundations with reasonable convergence rate and accuracy, and requires less computational effort, resources, and time.
{"title":"Higher-Order Finite Element Vibration Analysis of Circular Raft on Winkler Foundation","authors":"A. Dutta, D. Bandyopadhyay, J. Mandal","doi":"10.4018/ijgee.324112","DOIUrl":"https://doi.org/10.4018/ijgee.324112","url":null,"abstract":"On a Winkler foundation, solid circular plate vibration is examined using a higher-order finite element in polar co-ordinate system. The present formulation has developed a Mat-lab code to handle any boundary conditions. Validation of the code is carried out after the convergence studies. The results are compared to other researchers and show excellent conformity. Furthermore, a parametric analysis gave the first 10 natural frequency characteristics in tabular and graphical form. The authors conclude that the present formulation is straightforward, behaves exceptionally well for thin solid circular plates on elastic foundations with reasonable convergence rate and accuracy, and requires less computational effort, resources, and time.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85085828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low height embankments are widely used as road embankments for highways and rural roads in India. Sometimes, the construction of such types of embankments on soft foundation soil becomes mandatory. In addition to the problematic soft foundation soil, seismic excitation might also play a significant role in the stability of such an embankment. The present study analyses the response of a low height embankment with soft foundation soil under earthquake loading. Numerical simulations have been performed using FLAC2D program. A stiffer half-space with higher shear wave velocity (Vs) has been considered below the soft foundation soil and the earthquake loading has been applied at the bottom of this stiffer half-space. Simulation has been performed considering two different thicknesses of soft foundation soil. In addition to that, three different levels of earthquake shaking and Vs of the stiffer half-space have been considered in the analysis. Results have been presented in the form of PGA amplification, excess pore water pressure, horizontal, vertical static/seismic displacement, etc.
{"title":"Behavior of Low Height Embankment Under Earthquake Loading","authors":"Debabrata Ghosh, N. Roy, R. Sahu","doi":"10.4018/ijgee.315798","DOIUrl":"https://doi.org/10.4018/ijgee.315798","url":null,"abstract":"Low height embankments are widely used as road embankments for highways and rural roads in India. Sometimes, the construction of such types of embankments on soft foundation soil becomes mandatory. In addition to the problematic soft foundation soil, seismic excitation might also play a significant role in the stability of such an embankment. The present study analyses the response of a low height embankment with soft foundation soil under earthquake loading. Numerical simulations have been performed using FLAC2D program. A stiffer half-space with higher shear wave velocity (Vs) has been considered below the soft foundation soil and the earthquake loading has been applied at the bottom of this stiffer half-space. Simulation has been performed considering two different thicknesses of soft foundation soil. In addition to that, three different levels of earthquake shaking and Vs of the stiffer half-space have been considered in the analysis. Results have been presented in the form of PGA amplification, excess pore water pressure, horizontal, vertical static/seismic displacement, etc.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79852143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
According to design standards, uncertainty of dynamic foundation parameters are accounted in soil structure interaction (SSI) analysis by considering best estimate, upper and lower bounds. Site specific variability (coefficient of variation: Cv) cannot be directly established from limited site measurements. Codes prescribe a value of unity for such cases, which results in wide and often unrealistic range of foundation parameters for SSI. A Monte Carlo (MC) simulation based approach is proposed for calculation of site specific Cv from limited measurements. Along with 12% reduction of mean value, Cv could be reduced to 0.5, thereby enabling reduction of the aforementioned range. Adoption of code specified minimum Cv could accommodate 50% inaccuracy of input shear wave velocity, which justifies use of correlation equations (with inaccuracies reported between 20% and 35%) for generation of synthetic shear wave velocity profiles as substitute for or augmentation of site measurements.
{"title":"Estimation of Vs30 Bounds from Limited Soil Data Considering Uncertainty - A Practical Approach","authors":"","doi":"10.4018/ijgee.303588","DOIUrl":"https://doi.org/10.4018/ijgee.303588","url":null,"abstract":"According to design standards, uncertainty of dynamic foundation parameters are accounted in soil structure interaction (SSI) analysis by considering best estimate, upper and lower bounds. Site specific variability (coefficient of variation: Cv) cannot be directly established from limited site measurements. Codes prescribe a value of unity for such cases, which results in wide and often unrealistic range of foundation parameters for SSI. A Monte Carlo (MC) simulation based approach is proposed for calculation of site specific Cv from limited measurements. Along with 12% reduction of mean value, Cv could be reduced to 0.5, thereby enabling reduction of the aforementioned range. Adoption of code specified minimum Cv could accommodate 50% inaccuracy of input shear wave velocity, which justifies use of correlation equations (with inaccuracies reported between 20% and 35%) for generation of synthetic shear wave velocity profiles as substitute for or augmentation of site measurements.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80482384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main objective of this study is to understand the dynamic characteristic of pile foundations subjected to machine based vertical vibrations. To accomplish this objective, forced vibration field tests are performed on hollow steel single and pile group to obtain the vertical responses of the pile foundations. It is found from dynamic frequency-amplitude response curves that the resonant frequencies are decreases and resonant amplitudes are not proportional when excitation forces are increases which indicate the nonlinear characteristics of soil-pile systems. The values of resonant frequencies are found higher and resonant amplitudes are found lower when the number of pile is increase due to increase in soil-pile stiffness. For theoretical study, the continuum approach method is used to determine the analytical response curves of piles and further it is compared with the field test results. To understand the behavior of pile group, the variations of group efficiency ratio with varying frequencies are also predicted form the analysis.
{"title":"Machine Induced Vertical Responses of Single and Pile Group - Experimental and Theoretical Study","authors":"","doi":"10.4018/ijgee.298989","DOIUrl":"https://doi.org/10.4018/ijgee.298989","url":null,"abstract":"The main objective of this study is to understand the dynamic characteristic of pile foundations subjected to machine based vertical vibrations. To accomplish this objective, forced vibration field tests are performed on hollow steel single and pile group to obtain the vertical responses of the pile foundations. It is found from dynamic frequency-amplitude response curves that the resonant frequencies are decreases and resonant amplitudes are not proportional when excitation forces are increases which indicate the nonlinear characteristics of soil-pile systems. The values of resonant frequencies are found higher and resonant amplitudes are found lower when the number of pile is increase due to increase in soil-pile stiffness. For theoretical study, the continuum approach method is used to determine the analytical response curves of piles and further it is compared with the field test results. To understand the behavior of pile group, the variations of group efficiency ratio with varying frequencies are also predicted form the analysis.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87032835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Murugesan Sankara Narayanan, Joseph Antony Visuvasam, S. Chandrasekaran
In this paper, the behaviour of a soil-foundation system supported on a stone column-reinforced liquefiable soil strata is investigated through finite element analysis. The numerical analyses are performed on a five story reinforced concrete moment resisting building supported on a raft foundation. The influence of stone column slenderness ratio on liquefaction mitigation is studied by varying the length of stone columns at a constant area replacement ratio. The results are obtained based on the excess pore pressure, free-field soil settlement, foundation settlement, acceleration response, superstructure's inter-story drift, and lateral story displacement for each ground motion. The results showed that the liquefaction of free-field soil had a major impact on the foundation settlement and building lateral deformation. With the inclusion of stone columns, excess pore pressure ratio in the free-field region reduced considerably, which had immediate effects on the building's lateral deformation.
{"title":"Influence of Stone Columns on Seismic Response of Buildings Considering the Effects of Liquefaction","authors":"Murugesan Sankara Narayanan, Joseph Antony Visuvasam, S. Chandrasekaran","doi":"10.4018/ijgee.314222","DOIUrl":"https://doi.org/10.4018/ijgee.314222","url":null,"abstract":"In this paper, the behaviour of a soil-foundation system supported on a stone column-reinforced liquefiable soil strata is investigated through finite element analysis. The numerical analyses are performed on a five story reinforced concrete moment resisting building supported on a raft foundation. The influence of stone column slenderness ratio on liquefaction mitigation is studied by varying the length of stone columns at a constant area replacement ratio. The results are obtained based on the excess pore pressure, free-field soil settlement, foundation settlement, acceleration response, superstructure's inter-story drift, and lateral story displacement for each ground motion. The results showed that the liquefaction of free-field soil had a major impact on the foundation settlement and building lateral deformation. With the inclusion of stone columns, excess pore pressure ratio in the free-field region reduced considerably, which had immediate effects on the building's lateral deformation.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83910674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In India piles are designed as per IS 2911:2010 (Part 1) for different soil conditions considering all the load criteria. But there is no such provision in Indian Standard Codes for designing piles in potentially liquefiable soils. In this paper, the design of pile foundation in liquefiable soil is discussed. The provisions for design of pile foundations in liquefiable soil from different codes of practice from different countries are studied and the design approaches for the same are discussed based on those studies (Puri et al. 2008). The load bearing capacity of a pile in liquefied soil and non-liquefied soil is made based on the force equilibrium approach. A standardize graph which may be useful for practicing engineers has been plotted. Further, a comparative study is made based on the force equilibrium approach in Indian conditions.
在印度，考虑到所有荷载标准，针对不同的土壤条件，根据IS 2911:2010(第1部分)设计桩。但在印度标准规范中，对于潜在液化土中桩的设计却没有这样的规定。本文对液化土中桩基础的设计进行了探讨。本文研究了不同国家的不同规范对液化土中桩基设计的规定，并在这些研究的基础上讨论了液化土桩基的设计方法(Puri et al. 2008)。基于力平衡法对液化土和非液化土中桩的承载力进行了分析。并绘制了一幅可供实践工程师参考的标准化图。在此基础上，对印度条件下的力平衡方法进行了比较研究。
{"title":"A Simplified Approach of Design Pile Foundation on Liquefiable Soil in India","authors":"S. Dutta, R. P. Nanda","doi":"10.4018/ijgee.292466","DOIUrl":"https://doi.org/10.4018/ijgee.292466","url":null,"abstract":"In India piles are designed as per IS 2911:2010 (Part 1) for different soil conditions considering all the load criteria. But there is no such provision in Indian Standard Codes for designing piles in potentially liquefiable soils. In this paper, the design of pile foundation in liquefiable soil is discussed. The provisions for design of pile foundations in liquefiable soil from different codes of practice from different countries are studied and the design approaches for the same are discussed based on those studies (Puri et al. 2008). The load bearing capacity of a pile in liquefied soil and non-liquefied soil is made based on the force equilibrium approach. A standardize graph which may be useful for practicing engineers has been plotted. Further, a comparative study is made based on the force equilibrium approach in Indian conditions.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87821758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, the effect of Soil Structure Interaction (SSI) of low, mid and high rise (G+1, G+4, and G+9 storey) buildings has been evaluated by nonlinear dynamic analysis using three-dimensional finite element method. Three types of uniform soils namely hard soil, medium soil and soft soil have been considered for the present analysis. These buildings have been subjected to Loma Prieta (1989) earthquake motion and Denali (2002) earthquake motion as near field and far field earthquake motions respectively under the above mentioned soil conditions. From the analysis, the horizontal displacements and percentage of drifts have been determined of all the storeys of the buildings under the above mentioned three soil conditions and the two earthquakes. Further, for all the cases fragility curves have been computed. Furthermore, on the basis of the fragility curve and seismic hazard curve of a region, Reliability Index (RI) have also been developed.
{"title":"Reliability-Based Fragility Analysis of RC Frame Buildings Considering Soil-Structure Interaction","authors":"A. Shiuly, D. Das","doi":"10.4018/ijgee.304911","DOIUrl":"https://doi.org/10.4018/ijgee.304911","url":null,"abstract":"In the present study, the effect of Soil Structure Interaction (SSI) of low, mid and high rise (G+1, G+4, and G+9 storey) buildings has been evaluated by nonlinear dynamic analysis using three-dimensional finite element method. Three types of uniform soils namely hard soil, medium soil and soft soil have been considered for the present analysis. These buildings have been subjected to Loma Prieta (1989) earthquake motion and Denali (2002) earthquake motion as near field and far field earthquake motions respectively under the above mentioned soil conditions. From the analysis, the horizontal displacements and percentage of drifts have been determined of all the storeys of the buildings under the above mentioned three soil conditions and the two earthquakes. Further, for all the cases fragility curves have been computed. Furthermore, on the basis of the fragility curve and seismic hazard curve of a region, Reliability Index (RI) have also been developed.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84564816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuzzy-Probabilistic Seismic Hazard Analysis (FPSHA) is performed for Chennai city, south India incorporating both the random and fuzzy uncertainties. Randomness is handled using Monte-Carlo simulation technique, and fuzziness is accounted in the hazard analysis using fuzzy logic. The magnitude of earthquakes and epicentral distances are fuzzified and used as inputs in the fuzzy inference rules. Fuzzy attenuation relationships are developed as consequence of the inference rules with the help of ground-motion models and ANFIS. The proposed FPSHA method has the advantage over the conventional hazard analysis methods in respect of its preciseness, efficiency, practicability and reliability. The ground motions compatible with the target spectrum (UHS) of 475 years return period are selected from the recorded accelerograms with appropriate scaling. The established spectrum compatible accelerograms are vital in the seismic analysis and design of infrastructure facilities, rehabilitation and strengthening of historical and critical structures.
{"title":"Seismic Hazard Analysis Using Fuzzy-Probabilistic Approach for Chennai City, South India","authors":"","doi":"10.4018/ijgee.302005","DOIUrl":"https://doi.org/10.4018/ijgee.302005","url":null,"abstract":"Fuzzy-Probabilistic Seismic Hazard Analysis (FPSHA) is performed for Chennai city, south India incorporating both the random and fuzzy uncertainties. Randomness is handled using Monte-Carlo simulation technique, and fuzziness is accounted in the hazard analysis using fuzzy logic. The magnitude of earthquakes and epicentral distances are fuzzified and used as inputs in the fuzzy inference rules. Fuzzy attenuation relationships are developed as consequence of the inference rules with the help of ground-motion models and ANFIS. The proposed FPSHA method has the advantage over the conventional hazard analysis methods in respect of its preciseness, efficiency, practicability and reliability. The ground motions compatible with the target spectrum (UHS) of 475 years return period are selected from the recorded accelerograms with appropriate scaling. The established spectrum compatible accelerograms are vital in the seismic analysis and design of infrastructure facilities, rehabilitation and strengthening of historical and critical structures.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89585515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study is to develop a method based on a theoretical background that can evaluate directly the response spectrum of a soil profile at the surface from a specified bedrock response spectrum. One-dimensional ground response analysis is mainly performed using linear (L) and equivalent linear (EQL) method. The interesting feature of this method is its possibility to evaluate, directly, the response spectrum of a soil profile at the surface, without the need of using the power spectral density or the Fourier amplitude spectrum. The results of the proposed method showed a good agreement compared with those obtained from the Shake software and from the random vibration theory (RVT) used in the Strata software.
{"title":"Linear and Equivalent-Linear Direct Transfer of Bedrock Response Spectrum to Free Surface","authors":"Mounia Menoun Hadj Brahim, H. Afra","doi":"10.4018/ijgee.310051","DOIUrl":"https://doi.org/10.4018/ijgee.310051","url":null,"abstract":"The aim of this study is to develop a method based on a theoretical background that can evaluate directly the response spectrum of a soil profile at the surface from a specified bedrock response spectrum. One-dimensional ground response analysis is mainly performed using linear (L) and equivalent linear (EQL) method. The interesting feature of this method is its possibility to evaluate, directly, the response spectrum of a soil profile at the surface, without the need of using the power spectral density or the Fourier amplitude spectrum. The results of the proposed method showed a good agreement compared with those obtained from the Shake software and from the random vibration theory (RVT) used in the Strata software.","PeriodicalId":42473,"journal":{"name":"International Journal of Geotechnical Earthquake Engineering","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81031651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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