bluuebunny/crossref_metadata_2025 huggingface dataset:
Cavern fire safety – overview of requirements and pragmatic solutions in Hong Kong
Authors: Kwan Julian SH , Tsang Leslie WH , Ng Fred , Cheuk Johnny , Au Gary
Published: April 2021

Hong Kong’s steep hilly terrain limits the growth of surface urban areas. In response to the society’s needs for land to support social and economic developments, the Government of Hong Kong Special Administrative Region is actively exploring the use of caverns as one of the innovative measures to supplement Hong Kong’s land resources. The development of cavern space is an attractive option to meet the land demand not only for “not-in-my-backyard” (nimby) type public utilities but also for a wide spectrum of uses including commercial, industrial and community type facilities. The development of cavern fire safety design in Hong Kong evolved from the first cavern project in around 1980s. The design guideline “Guide to Fire Safety Design for Caverns” was jointly established by Building Authority and Fire Services Department in 1994, by referring to overseas and local experience consolidated in the Study of the Potential Use of Underground Space (SPUN) in 1990. This guideline however was developed with a focus on caverns for use by low population public utilities such as sewage treatment works and water service reservoirs where the fire load is generally localised, closely controlled and relatively low. Whereas, other prescriptive fire safety guidelines commonly adopted in the Code of Practice for Fire Safety in Buildings 2011 (FS Code) and the Codes of Practice for Minimum Fire Service Installations and Equipment and Inspection, Testing and Maintenance of Installations and Equipment (FSI Code) were developed for typical surface buildings only. The existing fire design guidelines are found to be not fully compatible with the recent expanding spectrum of cavern usage in Hong Kong. Each cavern development type has its unique site setting and fire safety characteristics under the proposed usage (e.g. government facilities, industrial and commercial facilities like concrete batching/rock processing/asphalt production plants, data centres, logistics/warehouse facilities, etc.). Strictly following the prescriptive fire safety requirements and the design guidelines for typical buildings to these usages in cavern will pose immense technical issues/challenges to cavern projects and could also lead to unwarranted impacts on their functional operations. A more coherent fire safety design approach for new cavern projects is therefore needed to facilitate project proponents to plan cavern projects in the future. This paper provides an overview of fire safety issues for cavern development, and also discusses the practical solutions in formulating the associated fire safety strategies which have been adopted in the latest cavern projects in Hong Kong, covering the technical issues on fire resisting construction, means of escape, means of access for firefighting and smoke management.
A literature review of medical support in cave rescue and confined space medicine – implications in urban underground space development.
Authors: Goh J
Published: April 2021

Objective: To conduct a literature review and knowledge synthesis of medical support in cave rescue and confined space medicine (CSM), thereby, extrapolating the knowledge gained from cave rescue and CSM to consequence management in Urban Underground Space (UUS) development. Methodology: A review of current medical literature was conducted. Data sources: Search engines utilized include PubMed, Medline, Cochrane Library, Science Direct and Google Scholar. Results and Recommendations: The synthesized knowledge based on available literature was extrapolated to application during consequence management in UUS development. Conclusion: As underground urbanization progresses to create sustainable habitats for the world’s increasing population, city planners need to consider the need for consequence management in UUS. The knowledge and experience gleaned a posteriori from cave rescue and CSM should be utilised to optimize the planning of emergency response in an urban underground environment.
Behaviour of an underground metro station for different constitutive models - A study on the influence of Mohr-Coulomb and other advanced constitutive models using PLAXIS 2D for the proposed Chennai Metro Rail Phase 2 project
Authors: Kumar Pitchumani N , Kanchuboyina Ganesh Deepak , Anjana R K , Bugga Sai Krishna
Published: April 2021

The Phase 2 of the proposed Chennai Metro Rail Project contains underground stations of depths below ground varying from 20m for a 2 level station to 32m for a 4 level station. Diaphragm walls have been chosen for the purpose of earth retention during construction stage and also to be a part of the permanent structure. The centre part of the stations is constructed using top-down methodology and the ends of the station which are used for the purpose of TBM launching and retrieval activities are constructed using either bottom-up or top-down methodologies. The behaviour of the part of the station constructed using top down sequence will be different from the part constructed using bottom up sequence. The current study focusses on the comparison of the influence of the various constitutive models available in the FEM software package PLAXIS 2D such as the basic Mohr-Coulomb model and advanced models such as Hardening soil model and Hardening soil small strain stiffness (HSS) models on the bending moments, shear forces of the diaphragm walls, ground deformations, strut forces etc. This comparative study has been performed on both the top-down and bottom-up sequences and for the different ground conditions along the proposed second phase metro rail alignment in Chennai region of India.
Diagnostics of condition of soil lying in the foundation of sewer collectors and metro tunnels by crosshole sounding method in urban underground space
Authors: Arkhipov Aleksei
Published: April 2021

Non-destructive geophysical crosshole sounding method can be used to control and monitoring the condition of natural and improved soils. This work studies the application of the crosshole sounding method to determine the condition of soils lying in the foundations of sewer collectors and tunnels. The investigation uses crosshole sounding apparatus APZ-1 developed by LLC “Geodiagnostika”. The study considered the results of crosshole sounding of soils at the site of the reconstruction of the Church of The Icon of the Mother of God “Joy of All Who Sorrow” and on the section of buried metro tunnels between “Lesnaya” and “Ploschad Muzhestva” stations in St. Petersburg (Russia). The author postulates that crosshole sounding provides the most accurate information about the foundation soils for making a decision on strengthening them for trouble-free operation of sewer collectors and tunnels.
Three-Dimensional Design Method of Overhead Transmission Line Based on BIM Technology
Authors: Lv Zhengyu , Shi Jianyong , Chen Peizhi
Published: April 2021

Because of the high complexity and large scale of transmission line engineering, a large amount of data will be generated in the traditional two-dimensional (2D) design process, and the work of each stage is relatively independent. The design results are difficult to be effectively managed and integrated, and timely information interaction within and between specialties can not be achieved. BIM (Building Information Modelling) technology has powerful functions of digitalization and information management. This paper studies the application of BIM technology in three-dimensional (3D) design of overhead transmission lines. With the help of Revit platform and secondary development technology, combined with “Xinfu 110 kV transmission and transformation” project, a standardized family library of overhead transmission lines is established, and a set of algorithms for automatic sorting of insulator strings and automatic generation of overhead lines are developed, which realizes the parametric design of the lines in 3D environment. The whole process is centered on BIM information model database, which solves the problem of information management and interaction in traditional 2D design, and improves the design efficiency and quality.
Anti-Seismic Test Study on the Grid-Tube-Type Double Steel Plate and Infilled Concrete Composite Shear Wall
Authors: Zhang Xianlong , Liu Yang , Wang Tian , Xu Wenping
Published: April 2021

In this paper, three test models were cast about the grid -tube- type double steel plate and infilled concrete composite shear wall, the horizontal low cyclic loading test was carried out, and hysteresis curves and skeleton curves were got under different coaxial compression ratios. The results show that the new composite shear wall has many advantages, such as full hysteresis curve, high bearing capacity, high ductility and high energy dissipation capacity. Under the large displacement angle of 1/25 and cyclic loading of 80 times, the plastic hinge area still maintains the large stiffness and bearing capacity, which can effectively prevent the collapse of the structure under the action of a major earthquake. New composite shear wall has good seismic performance, which can realize the design requirements of high axial compression ratio, high ductility and thin thickness walls.
Nonlinear Analysis of Eccentrically Braced Frames against Progressive Collapse
Authors: Gao Qinglin , Yin Fuxin
Published: April 2021

Eccentrically braced frame (EBF) incorporates the advantages of lateral resisting systems from moment resisting frame (MRF) and concentrically braced frame (CBF) into a single structural system. In order to investigate the effects of brace and link length in resisting progressive collapse, a finite element model of 10-story planar steel frame were built and analyzed with the SAP2000 software through nonlinear static analysis and nonlinear dynamic analysis respectively. The results show that brace can obviously improve the performance of the structure no matter which kind of brace is adopted. The inverted V-shaped (IV) eccentrically braced frame has the highest capacity against progressive collapse and the Y-shaped eccentrically braced frame has the highest energy absorption capacity of the structure. Increasing the link length leads to an increase in deformation and energy absorption of the structure. The results of nonlinear static analysis could reflect the structural performance basically.
The Research on Approach of BIM-Based 3D Design for Transmission Line Project
Authors: Zhou Liang , Kan Jingsheng , Shi Jianyong , Zhu Pan
Published: April 2021

BIM (Building Information Modelling) technology has the advantages of visualization and informatization. But BIM technology is mainly used in the construction field, and the application of BIM technology in transmission project is less. This paper research the application of BIM technology in the three-dimensional design of transmission lines. Based on the Revit platform and using secondary development technology, the parameterized model library of transmission line was built by Revit, such as work wells, cable trenches and towers, and the three-dimensional curve fitting algorithm was applied to design the path of the transmission line, and finally the three-dimensional digital model of the transmission line was built. The research results in this paper can provide a new method for 3D design in the field of transmission project.
Study on the Influence of Reinforcement Corrosion on Concrete Safety Factors
Authors: Zhang Yu , Ge Huang Jun , Shu Liu Jing
Published: April 2021

In order to better study the corrosion of rebar inside reinforced concrete, the corrosion position of rebar inside concrete is judged. Put rusted rebar, no rusted rebar, mixed rebar (rust and non-rust) on one side of the concrete test piece, and mark the position of the rebar, use the four-polarization method to observe the resistivity and polarity of reinforced concrete, and study the concrete interior. The degree of corrosion of rebar, the corresponding relationship between the position change and its polarization rate, the results show that: the longer the age of concrete, the worse the conductivity of concrete, the polarization rate of rusted rebar is greater than the polarization rate of un rusted rebar, when rebar is pre-buried above concrete, The polarization rate measured by concrete is greater than that of reinforced pre-buried under concrete. The polarization rate of pre-buried rusted reinforced concrete, the polarization rate of pre-buried mixed rebar, and the polarization rate of pre-buried non-rusted reinforced concrete. It is shown that pre-buried rusted reinforced concrete is more likely to produce polarization effects. The results show that it is feasible to judge the degree of corrosion of steel bars inside concrete by using the four-polarization method.
Measuring Study on Energy Saving Performance of the Trombe Wall in School Building
Authors: Wang Tianpeng , Zhu Lin , Bai Deyuan , Gao Fawen , Wang Jianhua
Published: April 2021

The thermal engineering and energy saving performance of the Trombe wall of a laboratory building in a middle school of Lanzhou region in northwest China were measured and investigated. The results show that during the normal using period in winter 10 years after the building was built, the daily convection heat supply of single group vents is 6.89 kW, the daily average thermal efficiency of the Trombe wall is 18.4 %. In addition, in the process of using the building, it needs to notice that the ventilated channel must be maintained clean and unhindered status, the vents devices must be repaired periodically in order to ensure good opening and closing function, and the vents should be avoided blocking and the ventilation heating mechanism of the Trombe wall should be avoided destroying in later renovation or decoration of the building.
Dynamic Performance Analysis of Ancient Buildings Based on Soil-Structure Interaction
Authors: Sun Shengjie , Meng Zhaobo , Zhao Qingshuang , Zhao Tengfei , Jin Jie
Published: April 2021

This paper takes Guangyue Tower as the research object and uses ANSYS software to establish three finite element models of its upper timber structure, timber structure and high platform foundation and wooden structure, high platform foundation and soil mass. Through modal analysis, it is concluded that when the soil-structure interaction is considered, the natural frequency of the structure is reduced, and its influence on the high-order natural frequency of the structure is greater than the influence on the low-order natural frequency. Select El-Centro wave, Taft wave and artificial wave to analyze the dynamic performance. The results show that only considering the wood structure or wood structure and the high platform will make the calculated displacement smaller, so the influence of the existence of the foundation soil on the superstructure should be considered.
Structural Reliability Analysis Using Group Teaching Optimization Algorithm
Authors: Cheng Jiaming , Jin Hui
Published: April 2021

Conventional First order reliability method (FORM) usually encounters divergence and non-convergence for high nonlinear performance functions. This paper puts forward an improved FORM coupling with a newly raised metaheuristic optimization algorithm, that is, Group teaching optimization algorithm (GTO). The GTO algorithm is inspired by grouping teaching strategy, featured by no additional control parameters, and has shown excellent global search ability for high nonlinear problems. Thus, the GTO algorithm is utilized to solve the equivalent constrained optimization problem according to the first order reliability theory. The implementation procedure of the proposed method is then presented in this paper. A numerical example is employed to verify the performance of the proposed method. Traditional reliability methods and PSO-based FORM are also introduced to compared with the proposed approach. The simulation results prove that the proposed method provides good performance in terms of computational efficiency and accuracy.
Review of Short-Term and Long-Term Bond Properties Between Epoxy-Coated Reinforcement and Concrete
Authors: Wang Jizhong , Lu Shiwei
Published: April 2021

Epoxy-coated rebars have been widely used to prevent steel corrosion problems in marine infrastructures of coastal cities. Based on the extensive studies on the bond behavior of epoxy-coated bars, the factors affecting the bond strength of epoxy-coated bars and the relative bond ratio, i.e., the bond strength ratio of epoxy-coated bars to uncoated bars were analyzed. The recommendations for the use of epoxy-coated bars are presented based on the evaluation of the calculated model of the bond strength in the current codes and specifications, which may provide some useful guidance for the widespread applications of epoxy-coated bars in the future.
A Brand-New Composite Air Supply Scheme for Tall and Square-Built Buildings with Different Air Distribution Variations
Authors: Yao Jinhui
Published: April 2021

The composite air supply for tall space buildings has always grabbed the researchers’ attention. Tall and square-built spaces generally have more complex building structures, along with challenges such as high system energy consumption, poor sewage disposal efficiency, and difficulty in heat dissipation. In addition, tall and square-built space buildings will have a greater impact on the flow of indoor airflow with respect to the air inlet/outlet selection, layout position, and spray angle. Therefore, in order to choose a more suitable plan and create a more reasonable airflow organization form, we use CFD numerical simulation method to simulate the airflow organization of a tall and open-duplex-structured factory in mainland, China. By setting different air supply parameters and air supplier column parameters, the composite air supply scheme combining the tuyere type and the air supplier column type is evaluated respectively. The experimental results show the feasibility and innovation of this scheme to increase the exhaust air volume, reduce energy consumption, and improve the heating effect in tall and square-built space buildings, and also provide a stereotype for the future application of examples on air distribution in similar buildings.
Analysis on the Incentive Policy of Traditional Construction Model and Prefabricated Construction Model Based on Evolutionary Game Theory
Authors: Chen Jie
Published: April 2021

The development of prefabricated construction model is a major change in construction production methods. It is an important measure to promote supply-side structural reform and the development of new urbanization. It is conducive to saving resources and energy consumption, reducing construction pollution, shortening construction period and improving engineering quality and safety. It is also conducive to promoting the deep integration of the construction industry and infornatization industrialization, cultivating new industries, and promoting the resolution of excess capacity. In the promotion and implementation of this model, the positive incentives given by government departments are the compass to guide the steady progress of this model. This article analyzes the transmission mechanism of the incentive policy of the prefabricated construction model in China in this behavior based on evolutionary game theory, and puts forward some suggestions on how to improve China’s prefabricated construction model policy system.
Research on Steel Structure Deeping Design Application Practice
Authors: Yin Yong , Zeng Hong , Sun Yan , Ji Cuihua
Published: April 2021

The node forms of a steel structure project are complex and changeable, from small beam connection nodes to large joist and steel column connection nodes, there are all kinds of nodes, and it is quite difficult to deepen the design. The Deeping design always plays a vital role in the steel structure construction, and the quality of its design will be directly related to the strict and effective implementation and execution of the design drawings to some extent, so as to further supplement and improve the construction drawings. Therefore, this will be directly related to the construction progress of the whole project and construction quality. This paper combines the actual project, to deepen the design of the problems to be considered for analysis, and put forward countermeasures. Through the project comprehensive application, confirm the feasibility of relevant countermeasures, and hope that the follow-up similar projects can have reference and help.
Comparative Study on the Durability of Pile, Beam and Slab Reinforced Concrete Structure in Marine Environment
Authors: Zhang Dongfang , Xiong Jianbo , Wang Shengnian , Wu Qingfa , Shi Hua
Published: April 2021

The durability of coastal reinforcement suffers serious threaten by the aggressive chloride in marine environment. The repairment of structures under service or new construction design has become an important part with increasing the requirement of long service lives of infrastructure, while the applied repairment should be inconsistence with the corrosion condition of different concrete structure in the port. Herein, this paper comparatively discusses the various deterioration level of pile, beam and slab under the same marine environment, and provide the guiding principles for further repairment. The results show that the beam structure exhibits the worst performance among three typical reinforcement structures. The exposed rebars of beam structures are seriously corroded due to the chloride attack and result in low corrosion potential and serious concrete spalling. In contract, the slab structure exhibit better durability with intact appearance, low chloride penetration and high corrosion potential.
Analysis on the Selection of Prefabricated Box-Shaped Steel Grid-Concrete Composite Thin-Shell Roof Structure
Authors: Hong Cheng , Yu Jiaxing , Zhang Baohua , Liu Kai , Ming Xia
Published: April 2021

The new fabricated box-shaped steel grid-concrete composite thin-shell roof structure is a new structure based on the large-span steel-concrete composite thin-shell roof. An assembly unit composed of thin-walled steel ribs with bolt holes, a steel bottom plate, and concrete, and a thin-shell roof structure formed by assembly connection between the assembly units. A comparative analysis of the deformation and stress of the flat roof and arched roof structure shows that when the span is less than 30m, the difference between the deformation and stress of the two structures is not large, and it is more reasonable to choose the flat assembled composite roof structure. The construction difficulty is lower. When the span is 40m, the maximum vertical displacement of flat roof and arched roof are 53.73mm and 17.81mm respectively, and the difference gradually increases from 40m. After the span exceeds 40m, the stress between the steel box and concrete of the flat roof structure. The ratio increases sharply, and the arched roof shows a uniform change trend. The material utilization rate of the arched roof is higher than that of the flat roof.
Finite Element Modeling Method and Analysis of Self-Compacting Concrete Prestressed T-Beam
Authors: Guo Jiafu , Qi Bing , Geng Wenlin , Fu Fengjiao , Cai Guangzhi , Zhang Yankun
Published: April 2021

Self-compacting concrete could be poured under the action of gravity, without vibration, and has good working performance. It could reduce the noise during production, and reduce the labor of workers. In recent years, more and more scholars begin to study the concrete. In this paper, ABAQUS finite element software is used to simulate the self-compacted concrete prestressed T-beam under different parameters, using the self-compacting concrete constitutive model. The cooling method is used to simulate the prestress applying, and the performance of beam is analyzed. It is found that the bearing capacity of the member improves with the increasing of the reinforcement ratio, the prestress increases the stiffness of the member, and reduces the deflection of the member, but the ductility is reducing with the increasing of prestress.
Research Hotspots and Tendency of Green Building Based on Bibliometric Analysis
Authors: Wang Qiankun , Zhu Ke , Guo Zeng , Shen Wenzhong , Kang Xianwei
Published: April 2021

Green building is a research hotspot in the field of Construction Engineering in recent years. This paper is based on 987 articles collected from the web of Science (WOS) core collection database, using Excel as the data statistical tool, the statistical research is carried out from the aspects of time output, hot institutions, hot journals, hot authors; VOSviewer is used to analyze the knowledge graph of hot authors and hot countries and regions, CiteSpace is used to analyze the co-occurrence words and burst words of Keywords, and the frontier of international green building research is obtained. The results show that: the research process of green building can be divided into three main stages: initial development, stable development, rapid development; At present, the eight major research topics are green roof, comparative assessment, building health, conventional building material, engineering design, building green, indoor environment quality, low-carbon integrated power grid.
Connection Strength of Undercut Anchorage Stone Cladding
Authors: Wang Zuohu , Shao Mingzhe , Gao Zhanguang , Yao Yuan
Published: April 2021

Experiments were conducted on seventy-two stone panels to investigate the connection strength of undercut anchorage stone cladding. The following factors were considered in this study: the stone type, the distance between the hole center and the edge of the plate, the hole depth and the diameter and type of the undercut anchor. The results show that the stone type and anchor depth are the factors that most strongly influence the anchorage strength. The distance between the hole center and the edge of the plate are secondary factors. The connection strength increases when the distance between the hole center and the edge of the plate from 40 mm to 60 mm. The anchorage strength of percussion anchor is approximately 10% higher than that of a screw-in anchor under the same conditions.
Research on Simulation Method of Steel-Concrete Composite Beam with Finite Element
Authors: Chen Fan , Ai Zubin , Zhou Lingyuan , Wang Chao , Hou Shengjun
Published: April 2021

The performance of composite girder double element model and composite cross-section model in the finite element analysis of composite beam were introduced, and three simulation method of the interface in the composite beam was studied, and then the three finite element modeling method of were adopt to analysis a composite beam under different load, and two simulation models including shrinking and the creep effect were computed. It is concluded from the computational results, when the mesh of dual element model is refined, the difference between the calculation results of the dual element model and the transformed section model remains very small, which means that dual element model can meet the requirements of calculation accuracy in case of the fine mesh size.
Analysis of Bearing Capacity of Steel-Concrete Composite Beams Considering Interface Slip Effect
Authors: Yang Song , Chen Fan , Ai Zubin , Zhou Lingyuan , Cao Zhensheng
Published: April 2021

Bearing capacity of the composite beam is analysis with three nonlinear finite element methods in the thesis, in which Hognostand’s uniaxial compression equation and BKIN model was applied to represent the constitutive relationship of concrete and steel in consideration of nonlinearity of concrete and the yield and strengthening characteristics of steel respectively. The interface slip between steel and concrete in composite beam is reasonably taken into account in the analysis with two methods. Those methods are compared according to the finite element analysis result, and the character of those methods are discussed and verified with the experimental result.
Development Research of the Double “L” Shaped Steel Plate-Concrete Composite Shear Wall
Authors: He Wenhui , Wan Yikun , Li Yuyu , Chen Lin
Published: April 2021

A double steel plates composite shear wall member composed of “L” elements (D-L-SCW) was proposed in this paper and its seismic behavior was preliminarily studied. With the shear-span ratio as test parameter, two specimens with actual ratio of 0.5 were constructed and tested in horizontal low-cycle reverse loading test. The failure modes, hysteretic behavior, skeleton curve, ductility and energy dissipation of the specimens were studied. Results showed that the suggested composite shear wall has significant seismic performance and can make more full use of the properties of both materials. The shear-span ratio mainly affected the peak load of the specimens, whilst it didn’t affect the overall deformation trend.
Research on Reinforcement Technology of Grid Bars with Oversized Slenderness Ratio
Authors: Wang Yong , Hu Ziwei , Dong Xu
Published: April 2021

The stiffness of axially loaded members is usually measured by slenderness ratio, which is the ratio of the calculated length of the member to the minimum turning radius of the member section. If the slenderness ratio is too large, the component is easy to produce bending deformation in the process of use. Under the action of dynamic load, it will produce large amplitude vibration, and it is easy to produce bending deformation in the process of transportation and installation. Therefore, the slenderness ratio of the component should be controlled in the design to make it not exceed the allowable slenderness ratio specified in the specification. Aiming at the problem that the slenderness ratio of space truss exceeds the limit, this paper puts forward the method of reducing the calculated length of members by adding supporting members or auxiliary members, so as to reduce the slenderness ratio of members, and studies the influence of increasing supporting members on the bearing capacity, deformation and seismic performance of space truss, so as to provide theoretical basis and guidance for the implementation of the reinforcement method.
Fire Performance of Insulated RC Beams Shear-Strengthened with CFRP Sheets
Authors: Mahmood Haris , Gao Wan-Yang , Hu Ke-Xu
Published: April 2021

In the literature, there is a lack of research on the fire performance of RC beams shear- strengthened with FRP laminates. This paper for the first time presents the fire endurance tests of insulated FRP shear-strengthened RC beams. A total of seven rectangular RC beams were constructed: three were tested at ambient temperature to determine their load-bearing capacity while the remaining four were first exposed to ISO 834 standard fire for 2.5 hours. Fire endurance tests indicated that the RC beam without insulation was characterized by shear failure due to the propagation of diagonal cracks. In contrast, the insulated FRP shear-strengthened RC beams could achieve a satisfactory fire resistance of 2.5 hours with small deflection responses under fire exposure. Because the additional fire protection layer provided adequate protection, the temperature responses recorded at the FRP-to-concrete interface were less than 250 °C, while the temperatures of the steel stirrups were around 120 °C during the entire fire exposure.
Fatigue Life of Welded Structures under Random Load Study on Frequency Domain Method
Authors: He Sai , Guan De Qing , Ping Luo Chao , Gao Fan
Published: April 2021

In this paper, based on the finite element software, the residual stress of the structure weld is obtained through simulation analysis. The influence of stress concentration is considered by using the mean square stress concentration factor; and the S-N curve equation of the structure is derived. then, the stress power spectrum density of dangerous parts is obtained by random response analysis; Then, the vibration mode of the welded structure is obtained by random response analysis, and the acceleration power spectral density of the structure is input, and then the stress power spectrum density of the dangerous part is obtained Finally, the appropriate stress probability density distribution model is selected to predict the fatigue life with S-N curve equation and Miner damage accumulation theory. The results show that the fatigue life predicted by this method is very close to that of rain flow counting method.
Interface Stress Element Method, Rigid Body Spring Model and Applied Element Method
Authors: Feng Biao
Published: April 2021

Interface Stress Element Method(ISEM), Rigid Body Spring Model(RBSM) and Applied Element Method(AEM) are typical connected discrete element methods derived from the same origin. Although there are many differences in their model compositions, expression forms, development paths and application situations, the three methods are closely related. In this paper, the commonalities and differences among ISEM, RBSM and AEM were expounded from five aspects: model composition, stiffness matrix for interface, formula for inter-element stress, theoretical system and analysis procedure. They discretize the domain with rigid blocks, but connect them using interface layers, distributed spring pairs and multiple spring pairs respectively. For homogeneous isotropic materials, the stiffness matrixes for RBSM are equal to that for ISEM, and there are only four items different in the stiffness matrix for AEM. The formula for inter-element stress of RBSM and AEM can be expressed by that for ISEM. The relationships among ISEM, RBSM and AEM were further clarified. RBSM and AEM are both special cases of ISEM. They can be incorporated into the theoretical system of Interface Stress Element Method. The three constitute a unified method family.
Experimental Study on Seismic Behaviour of Angle Steel Connections with Concealed Corbel of Fully Assembled Frame Beam and Column
Authors: Li Zhe , Qiao Chengyuan , Shi Manghua , Qiao Lu , Chen Xingyu
Published: April 2021

A method of “concealed corbel angle steel and bolt” is proposed to connect beams and columns of assembled frame. To study the seismic performance of the connection is designed an ordinary concrete beam specimen and three in the form of assembly connection specimens. The hysteretic curve, skeleton curve and ductility coefficient of cast-in-place specimen and angle steel connection specimen with concealed corbel are analysed by low cycle repeated load test. The influence of the angle steel thickness and the additional rib on the specimen in the assembly connection scheme is discussed. The test results show that: compared with ordinary cast-in-place concrete specimens, the assembly connection specimens have higher bearing capacity under the action of low-cycle reciprocating load. The hysteretic curves of the assembly and connection specimens were relatively full, and the displacement ductility coefficient was greater than 3.0, indicating that the assembly and connection specimens had good ductility. Increasing the thickness of the Angle steel and the additional ribs can improve the bearing capacity of the specimens. In particular, increasing the thickness of the Angle steel can significantly improve the bearing capacity of the specimens assembled and connected and reduce the damage of dark corbel before loading.
BIM Collaborative Design Solutions for Super High-Rise Buildings Over 250 Meters
Authors: Sun Hao , Ji Ruyan , Xie Wei
Published: April 2021

Super high-rise buildings are the product of human economic activities and technological progress. Construction of super high-rise buildings is difficult and involves many participants. Super high-rise buildings over 250 meters are facing more implementation difficulties, and design stage is the initial stage of the construction process. How to promote the design work of all participants in the design phase is a problem that must be solved in the design of super high-rise buildings. This research aims at 4 special difficulties in the design of super high-rise buildings with a height of 250 meters: multi-specialty collaborative design and management, Multi-party collaborative design and management, lightweight interaction of BIM models, data format exchange between software. This study adopts an integrated design platform to propose corresponding solutions to promote the collaborative design of super high-rise buildings. Finally, a super high-rise building design project is used as a case to demonstrate the research method.
Research on Construction Method of Semantic Dictionary in Architecture
Authors: Bi Zhenbo , Wang Huiqin , Lu Ying , Yang Hua
Published: April 2021

Creating a semantic dictionary is an important means of solving semantic problems in the BIM core technology system, and it is one of the cores of the application of BIM technology in the architectural field. At present, the research on IFD-like libraries in China is still in its infancy. How to construct a semantic dictionary suitable for the needs of the domestic civil engineering field is one of the key issues in domestic BIM technology research. In response to this problem, this paper proposes a method of constructing an IFD Library based on the ontology of the architectural domain. Firstly, it discusses the basic problems of IFD Library-like, then analyzes the root causes of semantic ambiguity in the application of BIM technology and the methods to solve semantic ambiguity, and finally explores and verifies the method of how to construct IFD-like Library based on the ontology of the architectural domain.
Study on Anti-Seismic Analysis of High-Rise Diaojiaolou Considering Pile-Soil Interaction
Authors: Xu Ning , Jia Chuanguo , Yang Pu , Zhang Qingzhang , Zhao Jianli
Published: April 2021

High-rise Diaojiaolou in mountainous areas have poorer seismic performance than flat high-rise structures due to their large structural loads and irregularities. Spring elements of equivalent stiffness are used to simulate the effect of nonlinear interaction between the piles and soil of high-rise Diaojiaolou. Research shows that the spring elements of equivalent stiffness can accurately simulate the seismic performance of high-rise Diaojiaolou. It is the most unfavorable state that the soil covers part of the long side of the Diaojiao plane, and the hanging legs exposed for a long time, which should avoid. The state of the soil covering the oblique angle part of the hanging legs has good lateral force stiffness.
Research on a Complete Set of Technologies for Assembled Residential Buildings with Steel-Structure Based on House Type Modularization and Component Standardization
Authors: Liu Yi-Feng , Luo Si-Shu , Wang Huan
Published: April 2021

The industrialization of assembled buildings with steel-structure is a major strategic demand in China nowadays in terms of the development of life cycle green buildings, the transformation and upgrading of housing industrialization, and the solution to steel industry overcapacity. Steel residential buildings have several advantages over traditional constructions: lightweight, good seismic performance, wind resistance, a high degree of prefabrication, rapid construction speed, and convenient construction; these are the factors promoting its rapid development in recent years. Based on the concept of house types modularization and parts standardization, the authors propose a series of standardized house types for assembled buildings with steel-structure, establish numerical evaluation method and optimization method of standardization rate based on Building Information Modelling(BIM). In this regard, we develop and rank performance criteria for assembled buildings by calculating the rate of prefabrication. Also, this study develops a complete set of technologies for the building envelope system, facility and pipeline system, and interior decoration system that matches with the structure system. Meanwhile, we apply the research results to engineering projects in practice and examine their applications. This research has proved useful for architects by providing a set of equations to evaluate the number of standardized parts.
Experimental Research and Finite Element Analysis on Blast Damage of Unreinforced Steel Fiber Concrete T-beam Structures
Authors: Peng Sheng , Wang Junyu , Cai Lujun , Jiang Tianhua , Han Fei
Published: April 2021

To reveal the dynamic behavior and damage mechanism of unreinforced concrete T-beam bridge under blast loads, three specimens were designed. Dynamic strain, acceleration and acoustic velocity pro- and post-blast of three specimens were measured respectively, and the generation, development process and distribution condition of cracks were investigated. The results indicated that ribbed slab fracture failure was a key to the unstable failure of the whole T-beam bridge specimen. Adding steel fiber evenly to the T-beam bridge deck can change the degree of blast damage from “severe damage” to “moderate damage”, which improves the explosion anti performance of the bridge structures. The damage evaluation results provide the basis for damage repair and reinforcement treatment after explosion.
Experimental Study on Shear Behavior of Fiber Reinforced Concrete Beams with Corroded Stirrups
Authors: Zou Zhenghao , Yang Guojiao
Published: April 2021

Through orthogonal test design, the influence factors of shear behavior of fiber reinforced concrete beams under different stirrup corrosion levels are studied. Three factors water cement ratio (A), fiber type (B) and fiber content (C) are determined, each factor contains three levels. 27 reinforced concrete beams of equal height and width with 3 corrosion levels were designed and subjected to continuous loading test after accelerated corrosion by electrification. According to the test results, the influence curve of each influencing factor on the test index is drawn, and the influence order of each influencing factor on the test index is determined according to the range analysis method.
Low Cycle Response Analysis of Welded Aluminum Alloy Box Castellated Beam
Authors: Li Chenghua , Gao Yalin , Yang Kaiyuan , Wang Xi
Published: April 2021

Welding aluminum alloy 6061-t6 aluminum alloy material is more and more widely used in construction engineering due to its light weight and high strength characteristics. Welding aluminum alloy box Castellated beam has great application value due to its unique section characteristics, in order to obtain more low cycle response curve of welding aluminum alloy box Castellated beam. In this paper, the constitutive relationship of domestic 6061-T6 aluminum alloy was obtained by laboratory test, and the finite element results were verified by low-cycle cycle test and full-scale test. ANSYS software is used to simulate the mechanical response of four welded aluminum alloy box Castellated beams under low cyclic load. The numerical results show that the hysteretic curves of aluminum alloy specimens are full, the pinching phenomenon is not obvious, and the welded aluminum alloy box Castellated beam shows strong overall stability. The seismic performance of welded aluminum alloy box Castellated beam is mainly controlled by expansion ratio, web height to thickness ratio and flange width to thickness ratio.
Corrosion Research and XCT Investigation of RC under Different Artificial Environment Simulation
Authors: Zhang XG , Zhao XY , Chen Y , Wang J
Published: April 2021

In this experiment, the common electric accelerated corrosion and drying-wetting cyclic corrosion test are compared, and the influencing factors (diameter of steel and thickness of protective layer) of the two corrosion methods are analyzed. When the constant current density was 100uA/cm2, the cracking time of the protective layer of the wetting-drying test samples was about 4 times that of the electrified test samples. For the two kinds of acceleration experiments, the cracking time of the protective layer increases with the increase of the diameter of the reinforcement and the thickness of the protective layer. Under the condition of accelerated corrosion by electrification, the diameter of reinforcement has a great influence on the cracking time of the protective layer, while the thickness of the protective layer has a relatively small influence. Under the condition of accelerated drying-wetting cyclic corrosion, the thickness of the protective layer has a great influence on the cracking time. The influence of the diameter of reinforcement is not obvious. In addition, we further explored the specimen with XCT. The rust patterns of the two samples are different.
Experimental Investigation on the Mechanical Properties of a Noval Bond-Type Anchorage for Carbon Fiber Reinforced Polymer Tendons
Authors: Ju Shiyuan , Zhou Zhi , Li Dongsheng
Published: April 2021

In order to effectively alleviate the stress concentration phenomenon of the inner-cone bond type anchorages and improve the ultimate anchoring capacity of the anchorages, a new kind of arcuate-cone bond type anchorage for carbon fiber reinforced polymer (CFRP) tendons was designed. The stress distribution curves, load-slip curves and failure modes of anchorages are obtained by tension test of a group of innner cone and arcuate cone anchors with different parameters. According to the test results, the influence of anchorage types, inclination angles and radius of arc on anchorage performance is analyzed. The results show that ultimate anchoring capacity is directly proportional to the slip between anchor cup and grout during loading. The slip of arcuate cone anchorage is larger than that of inner-cone anchorage, and the anchor with smaller inclination angles of anchor cup slips larger. The ultimate anchoring capacity of the novel arcuate cone bond-type anchorages is larger than that of the traditional inner cone anchorages, and the phenomenon of stress concentration on the surface of CFRP tendons is effectively alleviated by using arcuate cone anchorages.
Experimental Study on Flexural Toughness of Steel-Polyvinyl Alcohol Hybrid Fiber Reinforced Concrete
Authors: Su Ningyue , Fan Xiaochun
Published: April 2021

In order to study the flexural toughness of Steel(S)-Polyvinyl Alcohol (PVA) Hybrid Fiber reinforced Concrete, 10 specimens of hybrid fiber reinforced concrete with dimensions of 100 mm × 100 mm× 400 mm were studied by four point bending test. The load-deflection curve of hybrid fiber reinforced concrete beam was obtained, and its toughness was evaluated by flexural toughness index method. The results showed that the simultaneous incorporation of steel fiber and PVA fiber greatly improves the ultimate load and toughness index of concrete during bending failure, and fiber concrete has obvious strain hardening phenomenon. When PVA fiber volume content is 0.75% and steel fiber volume content is 1.25%, hybrid fiber concrete shows good positive hybrid effect, which is the most ideal to improve the bending performance of concrete matrix. And the research conclusion provides reference for the design and engineering application of hybrid fiber concrete.
The Micro Analysis and Influence of Nano SiO2 on High-Temperature Compressive Performance of Steel Fiber Reinforced Concrete (SFRC)
Authors: Yan Lan , Ming Xing Yong , Wen Li Shi , Li Jijun
Published: April 2021

This paper investigated the compressive strength of the normal concrete (NC), the steel fiber reinforced concrete (SFRC), the Nano normal concret (NNC) and the Nano-steel fiber reinforced concrete (NSFC) at the high temperature. On the other hand, Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to analyse Micro-Structure and Matrix phase structure at different temperatures. Results presented that the peak values of compressive strength of four types of concrete under high temperature appeared under 200°C.The compressive strength of NSFC was 77.45 Mpa under 200°C, respectively being 1.13, 1.21 and 1.34 times of those of SFRC, NNC and NC. Nano SiO2 could go through secondary hydration reaction with cement hydration product Ca(OH)2 so as to reduce Ca(OH)2 content and refine Ca(OH)2 crystals, transform Ca(OH)2 having adverse effect on strength into C-S-H gels and improve structural compactness. Therefore, addition of nano SiO2 could obviously improve high-temperature compressive strengths of the concrete, and it especially played a significantly role in improving compressive strength of SFRC.