The flat-roof and four-slope folded plate structure is a space thin-walled structure composed of four trapezoidal plates and a rectangular plate parallel to the bottom surface, which is widely used in various engineering applications. In order to clarify the force transmission path and stress distribution law under the action of this structural load, the folded plate structures were made by utilizing the plexiglass with the thicknesses of 3 and 4 mm, respectively, and had the simple support on opposite sides and fixed support on another opposite side. Then, the static load tests and ANSYS finite element analysis were implemented, and the results were compared. It shows that the test results are basically consistent with the finite element calculation results, the maximum stress values of the folded plate structure along the X and Y directions appear in the same position, and the maximum stress value of a 3 mm thick folded plate structure is greater than that of 4 mm. The junction position of the roof and the slope plate is the dangerous section, and the special treatment should be made for this section to prevent the damage of folded plate structure in the practical engineering. Moreover, some reasonable measures also should be taken to meet the design requirements of the plate–plate junction position.
平顶四坡折板结构是一种由四块梯形板和一块平行于底面的矩形板组成的空间薄壁结构，在各种工程应用中被广泛使用。为了弄清该结构荷载作用下的传力路径和应力分布规律，利用厚度分别为 3 毫米和 4 毫米的有机玻璃制作了折叠板结构，其对边为简支梁，另一对边为固定支梁。然后进行了静载荷试验和 ANSYS 有限元分析，并对结果进行了比较。结果表明，试验结果与有限元计算结果基本一致，折叠板结构沿 X 和 Y 方向的最大应力值出现在相同位置，且 3 mm 厚折叠板结构的最大应力值大于 4 mm 厚折叠板结构的最大应力值。屋面与斜板的交接位置是危险地段，在实际工程中应对折板结构的这一地段进行特殊处理，以防止折板结构的破坏。此外，还应该采取一些合理的措施来满足板与板交接位置的设计要求。
{"title":"Mechanical Performance Investigation of a Flat-Roof and Four-Slope Folded Plate Structure","authors":"Yan Yang, Meng Zhan, Yanfei Huang","doi":"10.1155/2024/2818930","DOIUrl":"https://doi.org/10.1155/2024/2818930","url":null,"abstract":"The flat-roof and four-slope folded plate structure is a space thin-walled structure composed of four trapezoidal plates and a rectangular plate parallel to the bottom surface, which is widely used in various engineering applications. In order to clarify the force transmission path and stress distribution law under the action of this structural load, the folded plate structures were made by utilizing the plexiglass with the thicknesses of 3 and 4 mm, respectively, and had the simple support on opposite sides and fixed support on another opposite side. Then, the static load tests and ANSYS finite element analysis were implemented, and the results were compared. It shows that the test results are basically consistent with the finite element calculation results, the maximum stress values of the folded plate structure along the <i>X</i> and <i>Y</i> directions appear in the same position, and the maximum stress value of a 3 mm thick folded plate structure is greater than that of 4 mm. The junction position of the roof and the slope plate is the dangerous section, and the special treatment should be made for this section to prevent the damage of folded plate structure in the practical engineering. Moreover, some reasonable measures also should be taken to meet the design requirements of the plate–plate junction position.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"11 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140591059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Structural health monitoring and damage identification aim to detect the internal damage and evaluate the health conditions of the practical engineering structure, which has been the most popular research field for several decades. The sensitivity-based method incorporated with the regularization techniques is the classical and useful approach, and it can obtain accurate damage detection results. However, with the development of civil engineering structures, this classical method faces two problems: one is it is only applied to simple structures rather than full-scale structures, and second is the iterative calculation efficiency is lower. Therefore, aiming at these drawbacks, the two improvement strategies have been introduced to the original method for its enhancement in the application potential and computational efficiency. The proposed method has been verified based on two examples, i.e., a numerical steel truss with 144 elements and a full-scale experimental steel truss with 160 elements. The results prove that the proposed method has better efficiency and good application potential in the practical full-scale engineering structure.
{"title":"Damage Identification of Full-Scale Steel Truss Structure Based on Model Condensation and Mean-Value Normalization Regularization Techniques","authors":"Huihui Chen, Haidong Zhang, Xiaojing Yuan","doi":"10.1155/2024/5520052","DOIUrl":"https://doi.org/10.1155/2024/5520052","url":null,"abstract":"Structural health monitoring and damage identification aim to detect the internal damage and evaluate the health conditions of the practical engineering structure, which has been the most popular research field for several decades. The sensitivity-based method incorporated with the regularization techniques is the classical and useful approach, and it can obtain accurate damage detection results. However, with the development of civil engineering structures, this classical method faces two problems: one is it is only applied to simple structures rather than full-scale structures, and second is the iterative calculation efficiency is lower. Therefore, aiming at these drawbacks, the two improvement strategies have been introduced to the original method for its enhancement in the application potential and computational efficiency. The proposed method has been verified based on two examples, i.e., a numerical steel truss with 144 elements and a full-scale experimental steel truss with 160 elements. The results prove that the proposed method has better efficiency and good application potential in the practical full-scale engineering structure.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140591251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examines the widespread practice of upstream tailings dam construction in metallurgical mines in China, conducting comprehensive testing and research on tailings from various depositional zones of the Caijiagou tailings pond. Analysis of the test results from three types of tailings reveals a systematic relationship between the mechanical characteristics of tailings and their depositional zones: the farther from the dam, the finer the tailings particles, categorized as silty clay tailing, silt tailing, and sandy silt tailing. Consistent patterns were observed in the consolidated-drained shear strength and consolidated-undrained effective shear strength of these tailings. Among these, sandy silt tailing exhibited the highest strength, whereas silty clay tailing displayed the lowest. The dynamic stress–strain relationships of all three tailings types are described using the Hardin equivalent viscous-elastic model, where the initial dynamic shear modulus and the maximum dynamic shear stress in the model increased with effective confining pressure. The damping ratios exhibited a three-stage trend with increasing dynamic strain: gradual increase, rapid growth, and then gradual stabilization. Under various consolidated stress conditions, the ratio of the damping ratio to the maximum damping ratio versus the reduction in dynamic shear modulus showed a favorable linear relationship. Under vibration conditions, the dynamic shear stress corresponding to tailings failure increased with higher effective confining pressure and consolidated stress ratio. Finally, this study summarizes the parameters and indicators related to the saturated tailings of iron mines used in the research. Our work provides a foundation and reference for the design of tailings dams and the development and utilization of abandoned tailings ponds.
{"title":"Mechanical Characteristics of Tailings in Different Depositional Zones: A Case Study of Caijiagou Tailings Pond in Shaanxi, China","authors":"Longfei Zhang, Zaiqiang Hu, Hongru Li, Haicheng She, Qiuxiang Qin, Xiaoliang Wang","doi":"10.1155/2024/8659304","DOIUrl":"https://doi.org/10.1155/2024/8659304","url":null,"abstract":"This study examines the widespread practice of upstream tailings dam construction in metallurgical mines in China, conducting comprehensive testing and research on tailings from various depositional zones of the Caijiagou tailings pond. Analysis of the test results from three types of tailings reveals a systematic relationship between the mechanical characteristics of tailings and their depositional zones: the farther from the dam, the finer the tailings particles, categorized as silty clay tailing, silt tailing, and sandy silt tailing. Consistent patterns were observed in the consolidated-drained shear strength and consolidated-undrained effective shear strength of these tailings. Among these, sandy silt tailing exhibited the highest strength, whereas silty clay tailing displayed the lowest. The dynamic stress–strain relationships of all three tailings types are described using the Hardin equivalent viscous-elastic model, where the initial dynamic shear modulus and the maximum dynamic shear stress in the model increased with effective confining pressure. The damping ratios exhibited a three-stage trend with increasing dynamic strain: gradual increase, rapid growth, and then gradual stabilization. Under various consolidated stress conditions, the ratio of the damping ratio to the maximum damping ratio versus the reduction in dynamic shear modulus showed a favorable linear relationship. Under vibration conditions, the dynamic shear stress corresponding to tailings failure increased with higher effective confining pressure and consolidated stress ratio. Finally, this study summarizes the parameters and indicators related to the saturated tailings of iron mines used in the research. Our work provides a foundation and reference for the design of tailings dams and the development and utilization of abandoned tailings ponds.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"65 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhongyu Xu, Lucija Hanžič, Harry Asche, Jurij Karlovšek
The durability of shotcrete tunnel linings is significantly affected by restrained shrinkage cracking. Given the unique characteristics of shotcrete applied in tunnel linings, especially when dealing with accelerated shotcrete containing reinforcement fibres, it is necessary to upscale the ring test commonly used. This paper presents a comprehensive experiment using large ring tests with cast concrete to investigate the impact of upscaling ring test geometry. The two ring specimens demonstrated comparable cracking age (22 days) and strain measured in the steel ring, suggesting that consistent results can be obtained through the proposed instrumentation, calibration, and correction methods. Moreover, the estimated induced tensile stresses of the concrete rings (2.8 and 2.7 MPa) are slightly lower than the predicted tensile strength (3.3 MPa) at the age of cracking, which indicates that some driving forces contributing to restrained shrinkage cracking were not indicated in the strain gauge readings. Furthermore, the study identified multi-crack formation and additional potential causes for crack initiation, which include self-restraint due to the moisture gradient in the vertical direction, deflection of the concrete ring caused by its self-weight, and friction on the contact surface of the support. Therefore, optimising the geometry of the ring specimens and the apparatus is imperative to minimise additional driving forces and unmeasurable restraints for crack initiation, especially when employing the stress rate method to assess cracking potential.
{"title":"Large Ring Test for Evaluation of Restrained Shrinkage Cracking: Calibration and Experimental Trial","authors":"Zhongyu Xu, Lucija Hanžič, Harry Asche, Jurij Karlovšek","doi":"10.1155/2024/6698625","DOIUrl":"https://doi.org/10.1155/2024/6698625","url":null,"abstract":"The durability of shotcrete tunnel linings is significantly affected by restrained shrinkage cracking. Given the unique characteristics of shotcrete applied in tunnel linings, especially when dealing with accelerated shotcrete containing reinforcement fibres, it is necessary to upscale the ring test commonly used. This paper presents a comprehensive experiment using large ring tests with cast concrete to investigate the impact of upscaling ring test geometry. The two ring specimens demonstrated comparable cracking age (22 days) and strain measured in the steel ring, suggesting that consistent results can be obtained through the proposed instrumentation, calibration, and correction methods. Moreover, the estimated induced tensile stresses of the concrete rings (2.8 and 2.7 MPa) are slightly lower than the predicted tensile strength (3.3 MPa) at the age of cracking, which indicates that some driving forces contributing to restrained shrinkage cracking were not indicated in the strain gauge readings. Furthermore, the study identified multi-crack formation and additional potential causes for crack initiation, which include self-restraint due to the moisture gradient in the vertical direction, deflection of the concrete ring caused by its self-weight, and friction on the contact surface of the support. Therefore, optimising the geometry of the ring specimens and the apparatus is imperative to minimise additional driving forces and unmeasurable restraints for crack initiation, especially when employing the stress rate method to assess cracking potential.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"25 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaolu Li, Zhe Yang, Yan Zhao, Xinwu Wang, Xiaomin Xue, Xueming Wang
This study aims to investigate the effect of the ring plate on the mechanical performance of X-type tube-gusset joints. The failure modes, ultimate strengths, and failure mechanisms of X-joints with ring plates were investigated through experiments and finite element analyses. The results indicated that the ring plate and the chord within the effective range of the ring plate constituted the primary bearing structure of the X-joint. Increases in the ring plate thickness and width increased the ultimate strength of the X-joint. By considering the forces of the braces as a superposition of the bending moment and the force acting on the gusset of the X-joint, a simplified calculation method for the ultimate strength of X-joints was established. The derivation process was validated and refined through experiments and finite element analyses. Finally, a safe and reliable formula was derived for evaluating the ultimate strength of X-joints.
本研究旨在探讨环板对 X 型管桁架接头机械性能的影响。通过实验和有限元分析，研究了带环板 X 型接头的失效模式、极限强度和失效机理。结果表明，环板和环板有效范围内的弦构成了 X 型接头的主要支承结构。环板厚度和宽度的增加提高了 X 型连接的极限强度。通过将支撑力视为弯矩和作用在 X 型连接夹板上的力的叠加，建立了 X 型连接极限强度的简化计算方法。通过实验和有限元分析对推导过程进行了验证和完善。最后，得出了一个安全可靠的公式，用于评估 X 型连接的极限强度。
{"title":"Mechanical Performance of Tube-Gusset X-Joints Enhanced by Ring Plates","authors":"Xiaolu Li, Zhe Yang, Yan Zhao, Xinwu Wang, Xiaomin Xue, Xueming Wang","doi":"10.1155/2024/6929522","DOIUrl":"https://doi.org/10.1155/2024/6929522","url":null,"abstract":"This study aims to investigate the effect of the ring plate on the mechanical performance of X-type tube-gusset joints. The failure modes, ultimate strengths, and failure mechanisms of X-joints with ring plates were investigated through experiments and finite element analyses. The results indicated that the ring plate and the chord within the effective range of the ring plate constituted the primary bearing structure of the X-joint. Increases in the ring plate thickness and width increased the ultimate strength of the X-joint. By considering the forces of the braces as a superposition of the bending moment and the force acting on the gusset of the X-joint, a simplified calculation method for the ultimate strength of X-joints was established. The derivation process was validated and refined through experiments and finite element analyses. Finally, a safe and reliable formula was derived for evaluating the ultimate strength of X-joints.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"40 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Receiving inspection plays a crucial role in ensuring construction quality after the completion of engineering projects. Traditional inspection measurement methods, such as manual observation means and optical equipment measurement methods, have limitations in terms of the number of measurement sites and the range of measurements. These traditional methods fail to provide accurate curve parameters and continuous spatial morphology information for large-span curved bridge structures. This paper proposes a reverse model measurement method to address this issue. The reverse model is built based on point cloud data acquired by 3D laser scanning technology. Finally, take the Taizicheng No. 1 Bridge as an example, the validity of the proposed method is verified.
{"title":"Reverse Model for Curved Bridge Measurement Based on 3D Laser Scanning Technology","authors":"Xin Chen, Lihang Chen, Dong Liang","doi":"10.1155/2024/5594519","DOIUrl":"https://doi.org/10.1155/2024/5594519","url":null,"abstract":"Receiving inspection plays a crucial role in ensuring construction quality after the completion of engineering projects. Traditional inspection measurement methods, such as manual observation means and optical equipment measurement methods, have limitations in terms of the number of measurement sites and the range of measurements. These traditional methods fail to provide accurate curve parameters and continuous spatial morphology information for large-span curved bridge structures. This paper proposes a reverse model measurement method to address this issue. The reverse model is built based on point cloud data acquired by 3D laser scanning technology. Finally, take the Taizicheng No. 1 Bridge as an example, the validity of the proposed method is verified.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"31 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140591256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feng Xiong, Jintao Wang, Guohua Zhang, Xueming Shi, Hong Zheng, Junjie Hu
In the construction of the civil engineering infrastructure, the noise and vibration are affected by the geological conditions, adopting specific construction techniques based on the geological conditions is of great significance in suppressing the noise and vibration caused by the construction. To classify and evaluate the rock mass quality, the rock quality designation (RQD) is adopted widely in the geological and mining engineering. Traditionally, to obtain RQD, lengths of drilling core pieces are measured and RQD is calculated manually, which is labor-expensive and time-consuming. With the development of the computational power, the image treatment driven by the computer vision creates a potential approach to obtain RQD automatically. In the present work, the image treatment process with the aid of the object detection and the image segmentation is adopted to obtain RQD automatically, based on the similarity of features such as color and texture, the segment anything model is adopted to detect the rock cores in the image, then, the YOLOv8 algorithm is adopted to train the model, and the gap features of the rock chip segments are extracted for segmentation of different rock core segments. To test the performance of the proposed approach, 10 boreholes from Shapingba Railway Comprehensive Reconstruction Project are adopted to conduct the case study. Compared to the traditional manual approach, RQD obtained by the proposed approach is relatively accurate and obviously efficient, namely, the average error is less than 5% and the time consumed is less than 70%.
{"title":"Intelligent Algorithm for Rock Core RQD Based on Object Detection and Image Segmentation to Suppress Noise and Vibration","authors":"Feng Xiong, Jintao Wang, Guohua Zhang, Xueming Shi, Hong Zheng, Junjie Hu","doi":"10.1155/2024/3599911","DOIUrl":"https://doi.org/10.1155/2024/3599911","url":null,"abstract":"In the construction of the civil engineering infrastructure, the noise and vibration are affected by the geological conditions, adopting specific construction techniques based on the geological conditions is of great significance in suppressing the noise and vibration caused by the construction. To classify and evaluate the rock mass quality, the rock quality designation (RQD) is adopted widely in the geological and mining engineering. Traditionally, to obtain RQD, lengths of drilling core pieces are measured and RQD is calculated manually, which is labor-expensive and time-consuming. With the development of the computational power, the image treatment driven by the computer vision creates a potential approach to obtain RQD automatically. In the present work, the image treatment process with the aid of the object detection and the image segmentation is adopted to obtain RQD automatically, based on the similarity of features such as color and texture, the segment anything model is adopted to detect the rock cores in the image, then, the YOLOv8 algorithm is adopted to train the model, and the gap features of the rock chip segments are extracted for segmentation of different rock core segments. To test the performance of the proposed approach, 10 boreholes from Shapingba Railway Comprehensive Reconstruction Project are adopted to conduct the case study. Compared to the traditional manual approach, RQD obtained by the proposed approach is relatively accurate and obviously efficient, namely, the average error is less than 5% and the time consumed is less than 70%.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"47 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140590944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Naser Sameti, Ebrahim Ghiasvand, Ehsanollah Zeighami, Seyyed Mohammad Mirhosseini
This study aimed to investigate the combined influence of heat curing and partial replacement of silica fume on the long-term behavior of alkali-activated slag (AAS) mortar. Silica fume replacement levels of 0%, 5%, and 10% were examined, with curing conducted at temperatures of 23 ± 2 and 80°C. The alkaline activator consisted of sodium hydroxide solution (4 M) mixed with sodium silicate in a 3 : 1 ratio by weight. The performance of the fabricated specimens was evaluated through compressive strength testing, mass change analysis, X-ray diffraction, and scanning electron microscopy. Heat treatment resulted in improved performance of AAS mortars, while silica fume replacement also positively influenced mortar behavior. Notably, the 5% replacement rate yielded the most favorable outcomes. However, it was observed that the long-term compressive strength of AAS mortar specimens decreased significantly. Potential adverse factors contributing to this decline were discussed. Furthermore, the durability of mortar samples exposed to adverse conditions was investigated. Results indicated that the combined use of heat curing and a 5% silica fume replacement level produced the best overall performance.
{"title":"Long-Term Performance and Durability of Heat-Treated Alkali-Activated Slag Mortar Containing Silica Fume","authors":"Naser Sameti, Ebrahim Ghiasvand, Ehsanollah Zeighami, Seyyed Mohammad Mirhosseini","doi":"10.1155/2024/3969944","DOIUrl":"https://doi.org/10.1155/2024/3969944","url":null,"abstract":"This study aimed to investigate the combined influence of heat curing and partial replacement of silica fume on the long-term behavior of alkali-activated slag (AAS) mortar. Silica fume replacement levels of 0%, 5%, and 10% were examined, with curing conducted at temperatures of 23 ± 2 and 80°C. The alkaline activator consisted of sodium hydroxide solution (4 M) mixed with sodium silicate in a 3 : 1 ratio by weight. The performance of the fabricated specimens was evaluated through compressive strength testing, mass change analysis, X-ray diffraction, and scanning electron microscopy. Heat treatment resulted in improved performance of AAS mortars, while silica fume replacement also positively influenced mortar behavior. Notably, the 5% replacement rate yielded the most favorable outcomes. However, it was observed that the long-term compressive strength of AAS mortar specimens decreased significantly. Potential adverse factors contributing to this decline were discussed. Furthermore, the durability of mortar samples exposed to adverse conditions was investigated. Results indicated that the combined use of heat curing and a 5% silica fume replacement level produced the best overall performance.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"39 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The contradiction between coal mining and urban construction in coal resource-based cities is prominent, which greatly limits the sustainable development of these cities. Pan’an New City is a key mining-induced subsidence area in Xuzhou City, which presents significant challenges to the construction of the new city. Therefore, in order to ensure the safe construction of Pan’an New City, the residual deformation and stability of the goaf sites must be monitored and evaluated. Under such background, based on the measured leveling data of the mining-induced surface deformation in a coal mine near Pan’an New City, this paper first analyzed the accuracy of InSAR monitoring of surface deformation in coal mining subsidence area by SBAS-InSAR technology. Then, the SBAS-InSAR technology was used to monitor the surface subsidence rate and cumulative subsidence in the coal mining subsidence area of Pan’an New City, based on the 29 scene SAR data during Dec. 2020 and Jan. 2022. The results showed that the goaf site in the north and northwest of Pan’an New City is unstable, while the other areas are stable. Finally, according to the monitoring results, the suggestions have been put forward for the construction of Pan’an New Town on the goaf site. The research results have important theoretical and practical significance for the reuse of goaf sites in Pan’an New City and similar areas in Xuzhou.
{"title":"Goaf Site Stability Detection in the Overlap Area of Coal Mining Subsidence and Urban Construction","authors":"Guangli Dai, Hongjia Li, Chao Liu, Huaizhan Li, Youwei Chang, Yu Chen, Yandong Gao, Yafei Yuan, Wenqi Huo","doi":"10.1155/2024/5375733","DOIUrl":"https://doi.org/10.1155/2024/5375733","url":null,"abstract":"The contradiction between coal mining and urban construction in coal resource-based cities is prominent, which greatly limits the sustainable development of these cities. Pan’an New City is a key mining-induced subsidence area in Xuzhou City, which presents significant challenges to the construction of the new city. Therefore, in order to ensure the safe construction of Pan’an New City, the residual deformation and stability of the goaf sites must be monitored and evaluated. Under such background, based on the measured leveling data of the mining-induced surface deformation in a coal mine near Pan’an New City, this paper first analyzed the accuracy of InSAR monitoring of surface deformation in coal mining subsidence area by SBAS-InSAR technology. Then, the SBAS-InSAR technology was used to monitor the surface subsidence rate and cumulative subsidence in the coal mining subsidence area of Pan’an New City, based on the 29 scene SAR data during Dec. 2020 and Jan. 2022. The results showed that the goaf site in the north and northwest of Pan’an New City is unstable, while the other areas are stable. Finally, according to the monitoring results, the suggestions have been put forward for the construction of Pan’an New Town on the goaf site. The research results have important theoretical and practical significance for the reuse of goaf sites in Pan’an New City and similar areas in Xuzhou.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"37 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper conducts compressive strength tests on foam concrete prepared under four factors and three levels through the design of orthogonal experiments. It delves into the phase change rules of the load–displacement curves obtained under various mix proportions. Furthermore, based on the 1-day and 3-day compressive strength values, the study explores different mix proportion results using range analysis and variance analysis methods, thereby determining the optimal mix proportion that can satisfy the maximum 1-day and 3-day compressive strength values. The results indicate that the compression process of rapid-hardening foam concrete includes four stages: initial compaction stage, elastic stage, yielding stage, and plateau stage, with each stage having different causes. Additionally, the sensitivity sequence of factors affecting the 1-day and 3-day compressive strength of rapid-hardening foam concrete is respectively rapid sulfoaluminate cement (α) > water-reducing agent content (δ) > foam content (β) > water-cement ratio (γ) and rapid sulfoaluminate cement (α) > water-cement ratio (γ) > foam content (β) > water-reducing agent content (δ). With 100% sulfoaluminate cement content, the 1-day and 3-day compressive strength values can reach 1.7054 and 2.5471 MPa, respectively, which are 13 times and 7 times the minimum values of 1-day and 3-day compressive strength under other admixtures. The analysis shows that the content of rapid sulfoaluminate cement has the most significant effect on the 1-day and 3-day compressive strength of rapid-hardening foam concrete, with foam content having the least impact on 1-day compressive strength and water-reducing agent content having the least impact on 3-day compressive strength. By integrating range analysis and variance analysis, the optimal mix proportion that simultaneously satisfies the maximum 1-day and 3-day compressive strength is determined to be 100% content of rapid-hardening sulfoaluminate cement, 4% foam content, 0.55% cement ratio, and 0.12% admixture content. Overall, this study provides theoretical support for the research and development of new rapid-hardening foam concrete materials and has significant practical implications for the emergency repair and construction of infrastructure projects.
{"title":"Optimal Mix Design and Mechanical Properties of Rapid-Hardening Foam Concrete","authors":"Yuan Liu, Danni Zhao, Ruibo Yin, Qiang Li, Xiong Wu, Xianglong Zeng, Wei Qiao, Jiangbo Xu","doi":"10.1155/2024/6232941","DOIUrl":"https://doi.org/10.1155/2024/6232941","url":null,"abstract":"This paper conducts compressive strength tests on foam concrete prepared under four factors and three levels through the design of orthogonal experiments. It delves into the phase change rules of the load–displacement curves obtained under various mix proportions. Furthermore, based on the 1-day and 3-day compressive strength values, the study explores different mix proportion results using range analysis and variance analysis methods, thereby determining the optimal mix proportion that can satisfy the maximum 1-day and 3-day compressive strength values. The results indicate that the compression process of rapid-hardening foam concrete includes four stages: initial compaction stage, elastic stage, yielding stage, and plateau stage, with each stage having different causes. Additionally, the sensitivity sequence of factors affecting the 1-day and 3-day compressive strength of rapid-hardening foam concrete is respectively rapid sulfoaluminate cement (<i>α</i>) > water-reducing agent content (<i>δ</i>) > foam content (<i>β</i>) > water-cement ratio (<i>γ</i>) and rapid sulfoaluminate cement (<i>α</i>) > water-cement ratio (<i>γ</i>) > foam content (<i>β</i>) > water-reducing agent content (<i>δ</i>). With 100% sulfoaluminate cement content, the 1-day and 3-day compressive strength values can reach 1.7054 and 2.5471 MPa, respectively, which are 13 times and 7 times the minimum values of 1-day and 3-day compressive strength under other admixtures. The analysis shows that the content of rapid sulfoaluminate cement has the most significant effect on the 1-day and 3-day compressive strength of rapid-hardening foam concrete, with foam content having the least impact on 1-day compressive strength and water-reducing agent content having the least impact on 3-day compressive strength. By integrating range analysis and variance analysis, the optimal mix proportion that simultaneously satisfies the maximum 1-day and 3-day compressive strength is determined to be 100% content of rapid-hardening sulfoaluminate cement, 4% foam content, 0.55% cement ratio, and 0.12% admixture content. Overall, this study provides theoretical support for the research and development of new rapid-hardening foam concrete materials and has significant practical implications for the emergency repair and construction of infrastructure projects.","PeriodicalId":7242,"journal":{"name":"Advances in Civil Engineering","volume":"120 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140169319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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