2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)最新文献

{"title":"Numerical analysis of the influence of pre-submergence of foundation pits on adjacent existing tunnels","authors":"Ming Xu, Xuemeng Xia, Xin-huan Liang, Xiaogang He, Changxin Xu, Ya-long Jiang","doi":"10.1109/ISTTCA53489.2021.9654713","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654713","url":null,"abstract":"Construction such as foundation pit precipitation and excavation can lead to redistribution of stresses in the soil, which can affect the adjacent existing tunnel and even cause cracking of the existing tunnel. Using a foundation pit in Nanchang as a case study, a numerical model was established using PLAXIS 3D software to investigate the effect of pre-submergence of the foundation pit on the adjacent existing tunnel, and the influence of factors such as the burial depth of the existing tunnel and the distance d between the tunnel and the foundation pit on the tunnel deformation was discussed. The results of the study show that as the depth of the tunnel increases, the tunnel deforms in the direction of the pit, with the bending moment, horizontal and vertical displacement of the tunnel being “large in the middle and small at the ends”, and the maximum value of the displacement decreases gradually, while the maximum value of the bending moment. In addition, when the burial depth is less than 1.0H, the influence of the spacing d is the greatest, the larger the spacing d the smaller the displacement value of the tunnel; while when the burial depth is greater than 1.0H, the burial depth becomes the main factor affecting the tunnel deformation.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124546382","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}

{"title":"Case analysis of landslide hazard risk identification induced by coupling effect of rainfall and reservoir water level change","authors":"Q. Song, X. L. Li, S. Ren, X. Cheng","doi":"10.1109/ISTTCA53489.2021.9654746","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654746","url":null,"abstract":"Engineering practice and research show that rainfall, earthquake, reservoir water level change and man-made engineering activities have an important impact on the stability of landslide. For the Three Gorges Reservoir Area in China, rainfall, especially heavy rainfall or continuous rainfall and the change of reservoir water level are often the most common and active factors inducing landslides. On the basis of discussing the landslide mechanism induced by rainfall and reservoir water level change, combined with the typical landslide hazard in the Three Gorges Reservoir area-Longshuigou landslide in Fengjie County of Chongqing city in China, this paper analyzes the landslide characteristics by means of detailed field survey and investigation, UAV aerial photography and comparative interpretation of remote sensing data. The analysis results show that (1) Longshuigou landslide is affected by the coupling effect of rainfall and reservoir water level change; (2) the landslide may collapse locally and the stability of landslide is relatively poor; (3) the prevention and control level of landslide disaster is grade III and its risk early warning level is blue.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130381961","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}

{"title":"Study on Physical and Mechanical Properties of the Water-rich Silt Fine Sand Stratum in an Area of Hangzhou","authors":"Huafeng Wang, Yangyi Zhang, Yanhua Gao, Yunfeng Guo, Fu-Shung Liu, Dongsheng Chen","doi":"10.1109/ISTTCA53489.2021.9654584","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654584","url":null,"abstract":"In order to deeply explore the basic physical and mechanical properties of the water-rich silt fine layer, taking the water-rich silt sand layer in Hangzhou city as the engineering background, a series of physical and mechanical tests including density, particle analysis, direct shear, unconfined compression and triaxial compression are carried out. On-site drilling reveals that the area in Hangzhou is mainly composed of sandy silt and silt fine sand mixed with silt. The particle analysis tests on the silt sand stratum soil show that the content of particles larger than 0.075 mm in the silt fine sand sample accounts for 50%~75% with a majority distribution range of 0.075~0.25mm. It is a typical silt fine sand with a single particle size and poor gradation. Laboratory mechanical tests of soil samples show that the unconfined compressive stress-strain curves of the soil sample show a characteristic of elastic-plastic-ductile. The failure mode is shear failure, and the angle of the shear fracture zone is about 65°. The cohesion and friction angle of the soil samples obtained from the direct shear, unconsolidated and undrained, and consolidated undrained triaxial tests are approximately 7.67~13.50KPa and 36.35~41.54° respectively. The results of three are closer but show an increasing trend. The research results can provide reference significance for engineering construction design and construction in Hangzhou area.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126709834","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}

{"title":"An Application of Finite Element-Infinite Element Coupled Boundary in Three-Dimensional Nonlinear Dynamic Response Analysis of Earth Dams With Deep Overburdened Layer","authors":"Junsong He, Yongheng Guo","doi":"10.1109/ISTTCA53489.2021.9654271","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654271","url":null,"abstract":"There are many risks of earthquake disaster acknowledged in the construction of embankment dam with deep overburdened layer in highly seismic region, and its dynamic response analysis under strong earthquake is the basis to predict and analyze the earthquake disaster. It is very important to carry out a three-dimensional nonlinear dynamic response analysis on the dam, of which the processing of the model boundary in numerical simulation determines the accuracy and calculation efficiency of the solution thereof. In this paper, two deep overburdened layer finite element boundary models and finite element-infinite element coupled boundary models were established to explore the applicability of infinite element in dynamic calculation with deep overburdened layer embankment dam based on a deep overburdened layer sand-gravel dam, and their dynamic responses under the anti-seismic effect were calculated. According to the analysis results, a significant impact was imposed by different boundaries on the extremum of dam acceleration, and the distribution characteristics of the maximum acceleration in the dam indicated a tendency of consistency. Furthermore, the interaction between the dam body and dam foundation shall be not ignored. The seismic waves gradually attenuated during deep overburdened layer propagation after the incidence of bed rock, and the dynamic response of dam body weakened with the increase of dam foundation area. Compared with the finite boundary model, the acceleration, dynamic displacement and dynamic shear strain calculated by the finite element -infinite element coupled boundary model indicated a significantly lower value against larger calculation results of the finite boundary model in dam foundation area, which is closer to the results of the finite element-infinite element coupled boundary model. Therefore, the finite element -infinite element coupled boundary can simulate the infinite domain of dam foundation effectively to realize the propagation and dissipation of seismic waves in deep overburdened layer and eliminate the adverse effects of seismic waves reflection on dam structure. The research results of this paper allow for decision-making basis for the design and construction of similar dams, as well as the prevention and control of earthquake disaster.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121177719","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}

{"title":"Vessel Behavior Prediction Based on Improved BP Neural Network","authors":"Kai Zheng, Guoyou Shi, Weifeng Li","doi":"10.1109/ISTTCA53489.2021.9654686","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654686","url":null,"abstract":"In view of the BP (Back Propagation) neural network is easy to fall into local optimization, particle swarm optimization (PSO) algorithm is used to optimize the BP neural network prediction model is proposed. The latitude, longitude, course and speed of the vessel in the AIS are selected as the characteristic parameters of the ship's navigation behavior, data at three consecutive times are input to the network, and the next data is output to train the network. The AIS data in the waters near Laotieshan are selected to verify the effectiveness and the capability of the proposed method. Comparing the prediction results of BP neural network, PSO-BP neural network, the results show that the PSO-BP neural network can jump out of the local optimal solution, and the prediction accuracy is higher.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126296208","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}

{"title":"Numerical analysis of the effect of pre-precipitation of foundation pits on adjacent group piles","authors":"Zhanjun Huang, Yi‐Xian Li, J. Peng, Yun-rong Zeng, Anyi Wang, Changjie Xu","doi":"10.1109/ISTTCA53489.2021.9654763","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654763","url":null,"abstract":"Pre-precipitation before excavation of the foundation pit will cause the displacement of the surrounding soil, which will affect the adjacent group piles in turn. Based on the foundation pit engineering of a station in Nanchang Metro Line 4, this paper establishes a three-dimensional fluid-solid coupling model of the influence of pre-dewatering on adjacent group piles with the help of PLAXIS 3D finite element software, studies the settlement pattern of the ground surface outside the pit and the mechanism of force deformation of the adjacent piles under the pre-dewatering condition, and further analyzes the influence of the pile length and pile diameter on the stress and deformation of the pile foundation. The calculation results show that the vertical displacement distribution of the surface outside the pit caused by precipitation is “spoon-shaped”, and the existence of the adjacent piles will hinder the displacement of the surrounding soil. The vertical displacement of the pile foundation gradually decreases with the increase of the pile depth and distance from the pit. When controlled variables are used, the increase in pile length and pile diameter leads to an increase in the ability to resist the surrounding soil displacement and a decrease in vertical displacement. Especially as pile diameter increases, the range of variation in vertical displacement of the pile foundation decreases significantly. The maximum axial force of the pile foundation tends to increase with the pile length or pile diameter increasing, and the position of the neutral point also moves downward due to its influence.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"91 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132481384","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}

{"title":"Research Progress on Post Cast Strip Construction Technology of Super Long Concrete Structure","authors":"Changming Hu, Ting Wang, Shouzhong Lin, X. Zhao","doi":"10.1109/ISTTCA53489.2021.9654569","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654569","url":null,"abstract":"The construction technology of post cast strip seriously affects the construction quality and structural safety. The current specifications do not give uniform and clear provisions on the width of post cast strip. This paper briefly expounds the current situation, advantages and disadvantages of post cast strip construction, and compares and analyzes the construction processes, applicable conditions, advantages and disadvantages of fast and easy closing net, inflatable core formwork and bubble membrane formwork; Wang tiemeng model is used to calculate the effect of post cast strip width on concrete shrinkage on both sides. The results show that the post cast strip width has little effect on shrinkage. The post cast strip construction technology of PVC pipe is proposed, which can improve the construction quality and realize green construction. Therefore, combined with the innovative post cast strip construction technology and specific working conditions, its width can be set optimally.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129968248","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}

{"title":"Determination of Mechanical Properties and Uncertainty Analysis of Welded Fabric","authors":"Cheng Li, Guoshou Liu, S. Wang, Zhiqiang Zhao","doi":"10.1109/ISTTCA53489.2021.9654689","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654689","url":null,"abstract":"In the past 30 years, the construction of Bridges in China has developed rapidly, and the proportion of traffic flow and heavy load has been increasing, which puts forward higher requirements on the mechanical properties of bridge deck pavement. The welded fabric in bridge deck pavement is easily fractured and caused diseases under the action of alternating tensile stress under the repeated action of automobile fatigue load. Therefore, it is of great practical significance to study the mechanical properties of cold rolled ribbed steel bar (CRB550) used for bridge deck pavement. The tensile tests of the base metal and the shear resistance of the joints of the reinforced mesh of bridge deck pavement were carried out and the main factors affecting the tensile test results of the base metal were analyzed through uncertainty. The influence of the loading rate of universal testing machine on the shear strength of welded fabric was analyzed by mathematical statistics method. The results show that the uncertainty introduced in the process of measuring the maximum force FM is the most important factor affecting the uncertainty of the tensile test results of the base metal. The test rate has a great influence on the shear strength of welded fabric joints. When the tensile rate is 50 times the normal rate, the shear strength increases by 19%.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130181108","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}

{"title":"Modeling and Analysis of Shanghai Tower Based on ANSYS Workbench","authors":"Guanzhong Hu, Shujing Zhu, R. Gao, Lingfeng Xiao","doi":"10.1109/ISTTCA53489.2021.9654785","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654785","url":null,"abstract":"Workbench ANSYS, a software based on the finite element method, provides powerful ways for the modal and harmonic response analysis to evaluate the dynamic characteristics of structures. This research aims to determine the inherent natural frequencies as well as total deformation of Shanghai Tower through simplified models. The result demonstrates diagrams of the first six modes and the harmonic response of the simplified exterior model. In addition, a telescopic model and a simplified interior model are built. We hope that this research would provide a reliable reference for the maintenance and forecast risks for Shanghai Tower, and insights for future modeling of the tower.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134448199","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}

{"title":"Research on the Disturbance Law on the Cable Tunnel Induced by the Foundation Pit Construction of Pile Enclosing Structure","authors":"Zhiguo Duan, Qian Li, Kaixuan Zhang, Wenjiang Li","doi":"10.1109/ISTTCA53489.2021.9654664","DOIUrl":"https://doi.org/10.1109/ISTTCA53489.2021.9654664","url":null,"abstract":"Based on the engineering geological conditions of Shijiazhuang city, this paper analyzes the impact of foundation pit construction of pile enclosing structure on the horizontal deformation of the piles and ground settlement, and the deformation and structural internal force on the adjacent cable tunnel. Based on the above, the influence of the distance between foundation pit and tunnel on the deformation and safety of cable tunnels are also discussed. The research results show that the surface settlement on the side with tunnel is less than that without tunnel after the excavation of the foundation pit. The longitudinal stress of the cable tunnel structure is the main factor to the safety of the structure, and the maximum longitudinal tensile stress is located the tunnel wall foot far away from the foundation pit. There existing no-linear increasing relationship between the distance and the safety factor of the cable tunnel.","PeriodicalId":383266,"journal":{"name":"2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133981185","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}