首页 > 最新文献

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

英文 中文
Numerical analysis of the influence of pre-submergence of foundation pits on adjacent existing tunnels 基坑预沉对相邻既有隧道影响的数值分析
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654713
Ming Xu, Xuemeng Xia, Xin-huan Liang, Xiaogang He, Changxin Xu, Ya-long Jiang
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.
基坑降水、开挖等施工会引起土体应力的重新分布,对相邻既有隧道产生影响,甚至引起既有隧道开裂。以南昌某基坑为例,利用PLAXIS 3D软件建立数值模型,研究基坑预沉对相邻既有隧道的影响,探讨既有隧道埋深、隧道与基坑距离等因素对隧道变形的影响。研究结果表明:随着隧道深度的增加,隧道沿基坑方向发生变形,隧道弯矩、水平位移和垂直位移呈“中间大、两端小”的趋势,且位移最大值逐渐减小,弯矩最大值逐渐减小。另外,当埋深小于1.0H时,间距d的影响最大,间距d越大,隧道位移值越小;当埋深大于1.0H时,埋深成为影响隧道变形的主要因素。
{"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}
引用次数: 0
Case analysis of landslide hazard risk identification induced by coupling effect of rainfall and reservoir water level change 降雨与水库水位变化耦合效应下滑坡灾害风险识别实例分析
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654746
Q. Song, X. L. Li, S. Ren, X. Cheng
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.
工程实践和研究表明,降雨、地震、水库水位变化和人为工程活动对滑坡的稳定性有重要影响。对于中国三峡库区来说,降雨,特别是强降雨或连续降雨以及水库水位的变化往往是诱发滑坡最常见和最活跃的因素。本文在探讨降雨和水库水位变化诱发滑坡机理的基础上,结合三峡库区典型滑坡灾害——重庆市奉节县龙水沟滑坡,通过实地详实调查、无人机航拍和遥感数据对比解译等手段,对滑坡特征进行了分析。分析结果表明:(1)龙水沟滑坡受降雨与水库水位变化的耦合效应影响;(2)滑坡可能发生局部垮塌,滑坡稳定性较差;(3)滑坡灾害防控等级为三级,风险预警等级为蓝色。
{"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}
引用次数: 0
Study on Physical and Mechanical Properties of the Water-rich Silt Fine Sand Stratum in an Area of Hangzhou 杭州某地区富水粉砂细砂地层物理力学特性研究
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654584
Huafeng Wang, Yangyi Zhang, Yanhua Gao, Yunfeng Guo, Fu-Shung Liu, Dongsheng Chen
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.
为深入探讨富水粉砂细层的基本物理力学特性,以杭州市富水粉砂层为工程背景,进行了密度、颗粒分析、直剪、无侧限压缩、三轴压缩等一系列物理力学试验。现场钻探表明,杭州地区主要由砂质粉砂和粉砂细砂混合粉砂组成。粉砂层土颗粒分析试验表明,粉砂细砂样品中大于0.075 mm的颗粒含量占50%~75%,多数分布范围为0.075~0.25mm。它是一种典型的粉砂细砂,粒度单一,级配差。室内土样力学试验表明,土样的无侧限压应力-应变曲线呈现弹塑性-延性特征。破坏方式为剪切破坏,剪切破碎带角度约为65°。直剪、未固结不排水和固结不排水三轴试验土样的黏聚角和摩擦角分别约为7.67~13.50KPa和36.35~41.54°。三者的结果较为接近,但均呈上升趋势。研究成果可为杭州地区的工程建设设计和施工提供参考意义。
{"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}
引用次数: 0
An Application of Finite Element-Infinite Element Coupled Boundary in Three-Dimensional Nonlinear Dynamic Response Analysis of Earth Dams With Deep Overburdened Layer 有限元-有限元耦合边界在深超载土坝三维非线性动力响应分析中的应用
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654271
Junsong He, Yongheng Guo
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.
高震区深超载层路堤坝施工存在诸多地震灾害风险,其在强震作用下的动力响应分析是预测和分析地震灾害的基础。对大坝进行三维非线性动力响应分析是非常重要的,数值模拟中模型边界的处理决定了其求解的精度和计算效率。本文以某深超载层砂砾坝为例,建立了两种深超载层有限元边界模型和有限元-无限单元耦合边界模型,探讨了无限单元在深超载层路堤坝动力计算中的适用性,并计算了它们在抗震作用下的动力响应。分析结果表明,不同边界对坝体加速度极值有显著影响,最大加速度在坝体内的分布特征呈一致性趋势。此外,坝体与坝基之间的相互作用也不容忽视。基岩发生后,在深超载层传播过程中,地震波逐渐衰减,坝体动力响应随坝基面积的增加而减弱。与有限边界模型相比,在坝基区域,有限元-无限单元耦合边界模型计算的加速度、动位移和动剪应变值明显较低,而有限边界模型计算结果较大,更接近有限元-无限单元耦合边界模型的计算结果。因此,有限元-无限单元耦合边界可以有效地模拟坝基的无限域,实现地震波在深超载层中的传播和耗散,消除地震波反射对坝体结构的不利影响。本文的研究成果可为同类大坝的设计和施工以及地震灾害的防治提供决策依据。
{"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}
引用次数: 0
Vessel Behavior Prediction Based on Improved BP Neural Network 基于改进BP神经网络的船舶行为预测
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654686
Kai Zheng, Guoyou Shi, Weifeng Li
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.
针对BP (Back Propagation)神经网络容易陷入局部寻优的问题,提出了采用粒子群优化(PSO)算法对BP神经网络预测模型进行优化。选择AIS中船舶的经纬度、航向和航速作为船舶航行行为的特征参数,连续三次将数据输入到网络中,再输出下一次数据对网络进行训练。以老铁山附近海域的AIS数据为例,验证了该方法的有效性和能力。将BP神经网络和PSO-BP神经网络的预测结果进行比较,结果表明PSO-BP神经网络能够跳出局部最优解,预测精度更高。
{"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}
引用次数: 0
Numerical analysis of the effect of pre-precipitation of foundation pits on adjacent group piles 基坑预沉降对相邻群桩影响的数值分析
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654763
Zhanjun Huang, Yi‐Xian Li, J. Peng, Yun-rong Zeng, Anyi Wang, Changjie Xu
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.
基坑开挖前的预降水会引起周围土体的位移,进而影响相邻群桩。本文以南昌地铁4号线某车站基坑工程为背景,借助PLAXIS三维有限元软件,建立了预脱水对邻近群桩影响的三维流固耦合模型,研究了预脱水条件下坑外地表沉降规律及邻近群桩受力变形机理。并进一步分析了桩长和桩径对桩基应力和变形的影响。计算结果表明,降水引起的基坑外表面竖向位移呈“勺形”分布,相邻桩的存在会阻碍周围土体的位移。桩基础的竖向位移随桩深和离坑距离的增加而逐渐减小。当采用控制变量时,桩长和桩径的增加导致抗周围土体位移能力的增强和竖向位移的减小。特别是随着桩径的增大,桩基础竖向位移的变化范围明显减小。桩基础最大轴力随桩长或桩径的增大而增大,中性点位置也受其影响向下移动。
{"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}
引用次数: 0
Research Progress on Post Cast Strip Construction Technology of Super Long Concrete Structure 超长混凝土结构后浇条施工技术研究进展
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654569
Changming Hu, Ting Wang, Shouzhong Lin, X. Zhao
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.
后浇带的施工工艺严重影响到施工质量和结构安全。现行规范对后铸钢条的宽度没有统一明确的规定。简要阐述了后浇条施工的现状、优缺点,并对快速易闭网、充气芯模板、气泡膜模板的施工工艺、适用条件、优缺点进行了比较分析;采用王铁萌模型计算后浇条宽度对两侧混凝土收缩的影响。结果表明,后浇铸带宽度对收缩率影响不大。提出了PVC管材后浇铸条施工工艺,提高了施工质量,实现了绿色施工。因此,结合创新的后浇带施工技术和具体的工作条件,可以对其宽度进行最优设置。
{"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}
引用次数: 0
Determination of Mechanical Properties and Uncertainty Analysis of Welded Fabric 焊接织物力学性能的测定及不确定度分析
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654689
Cheng Li, Guoshou Liu, S. Wang, Zhiqiang Zhao
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%.
近30年来,中国桥梁建设发展迅速,交通流量和重载比重不断增加,对桥面铺装层的力学性能提出了更高的要求。桥面铺装焊接织物在汽车疲劳荷载的反复作用下,在交变拉应力的作用下易发生断裂和病害。因此,对桥梁桥面铺装用冷轧带肋钢筋(CRB550)的力学性能进行研究具有重要的现实意义。对桥面铺装层配筋网节点进行了母材抗拉试验和抗剪试验,并通过不确定度分析了影响母材抗拉试验结果的主要因素。采用数理统计方法,分析了万能试验机加载速率对焊接织物抗剪强度的影响。结果表明,测量最大力FM过程中引入的不确定度是影响母材拉伸试验结果不确定度的最主要因素。试验速率对织物焊接接头的抗剪强度影响较大。当拉伸速率为正常速率的50倍时,抗剪强度提高19%。
{"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}
引用次数: 0
Modeling and Analysis of Shanghai Tower Based on ANSYS Workbench 基于ANSYS Workbench的上海中心大厦结构建模与分析
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654785
Guanzhong Hu, Shujing Zhu, R. Gao, Lingfeng Xiao
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.
基于有限元法的Workbench ANSYS软件为结构的模态响应和谐波响应分析提供了强有力的方法来评价结构的动力特性。本研究旨在通过简化模型确定上海中心大厦的固有固有频率和总变形。结果显示了简化后的外模前六阶振型及谐波响应图。此外,建立了伸缩模型和简化的内部模型。我们希望本研究能为上海中心大厦的维护和风险预测提供可靠的参考,并为今后上海中心大厦的建模提供参考。
{"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}
引用次数: 1
Research on the Disturbance Law on the Cable Tunnel Induced by the Foundation Pit Construction of Pile Enclosing Structure 围桩结构基坑施工对索道的扰动规律研究
Pub Date : 2021-11-12 DOI: 10.1109/ISTTCA53489.2021.9654664
Zhiguo Duan, Qian Li, Kaixuan Zhang, Wenjiang Li
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.
本文结合石家庄市的工程地质条件,分析围桩结构基坑施工对桩的水平变形和地面沉降的影响,以及对相邻电缆隧道的变形和结构内力的影响。在此基础上,讨论了基坑与隧道间距对电缆隧道变形和安全的影响。研究结果表明:基坑开挖后,有隧道一侧地表沉降小于无隧道一侧地表沉降。缆索隧道结构的纵向应力是影响结构安全的主要因素,而最大的纵向拉应力位于远离基坑的隧道壁脚处。缆索隧道的距离与安全系数呈非线性增长关系。
{"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}
引用次数: 0
期刊
2021 4th International Symposium on Traffic Transportation and Civil Architecture (ISTTCA)
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1