Numerical and experimental research on annular crossed cable-truss structure under cable rupture

The Annular Crossed Cable-Truss Structure（ACCTS） is a new type of Tensile Spatial Structure with a configuration suitable to cover large-span stadiums. Its configuration has potential to perform well in resisting disproportionate collapse. However, its disproportionate collapse resistance hasn＇t yet been analyzed in depth. In this study, numerical and experimental research was carried out to investigate the performance of ACCTS under cable rupture. The numerical analysis was done for ten cable-rupture plans using LS-DYNA（explicit method） and the experimental test on an ACCTS with a diameter of 17.15 m was performed for three cable-rupture plans. It is concluded that, while deflections increase with the number of removed cables, an ACCTS does not undergo a disproportionate collapse and it provides a promising structural concept for tensile spatial structures.

Cable-truss supporting system for gob-side entry driving in deep mine and its application

In order to solve the large deformation controlling problem for surrounding rock of gob-side entry driving under common cable anchor support in deep mine, site survey, physical modeling experiment, numerical simulation and field measurement were synthetically used to analyze the deformation and failure characteristics of surrounding rock. Besides, applicability analysis, prestress field distribution characteristics of surrounding rock and the control effect on large deformation of surrounding rock were also further studied for the gob-side entry driving in deep mine using the cable-truss supporting system. The results show that, first, compared with no support and traditional bolt anchor support, roof cable-truss system can effectively restrain the initiation and propagation of tensile cracks in the roof surrounding rock and arc shear cracks in the two sides, moreover, the broken development of surrounding rock, roof separation and extrusion deformation between the two sides of the roadway are all controlled; second, a prestressed belt of trapezoidal shape is generated in the surrounding rock by the cable-truss supporting system, and the prestress field range is wide. Especially, the prestress concentration belt in the shallow surrounding rock can greatly improve the anchoring strength and deformation resisting capability of the rock stratum;third, an optimized support system of ‘‘roof and side anchor net beam, roof cable-truss supporting system and anchor cable of the narrow coal pillar" was put forward, and the support optimization design and field industrial test were conducted for the gob-side entry driving of the working face 5302 in Tangkou Mine, from which a good supporting effect was obtained.

Analytical Study of the Cable-Truss Systems on the Glass Certain Walls with Vertical Uses

The aim of this study is to analyze of the cable-glass systems which are used on the glass curtain wall according to their types, degree, architectural and structural effects. The suspended glass system with pre-stressed cable truss (SGSPCT) is widely started to apply after the 1980’s with Serres building. The advantages of these systems are to provide the transparency on the fa?ades and speedy construction process with minimum materials. The disadvantages are: more expensive than other systems and so many details for the joints and load distribution calculations. There are three different architectural design typologies of the SGSPCT system. These are distance bridging systems, between floor system and independent body. These three different typologies can be seen on the same building at the same time. This system has been known as complex structure systems. The twenty five glass buildings which are designed in different systems have been analyzed during this study. After these analyses the five glass buildings which are designed with cable-truss system have been selected for scope of the study. These selected buildings have been included of three different cable-truss system typologies and degree. The methodology of this study is literature survey and building analyses method. The written and visual documents involve books, theses, reports, articles, magazines, drawings, internet sources and applied connection details of the glass buildings. The selected five glass buildings have been detailed analyzed with their architectural drawings, photographs and details. The study consists of five chapters including the introduction chapter. The general information of the glass building and cable-glass system has been mentioned in the first chapter. The structural features, details and analytical information on systems have been explained of the selected buildings in the second chapter. The detailed analyses of these selected buildings have been done according to their schematic drawings with the plans, sections and load distribution in the third chapter. The fourth chapter is discussion section. In this section, cable-truss systems have been compared with their advantages and disadvantages to the other systems. The fifth chapter is the last chapter, many advantages of cable-truss systems have been concluded that the use of glass substrates.

Seismic response of large-span spatial structures under multi-support and multidimensional excitations including rotational components

To achieve rational and precise seismic response predictions of large span spatial structures(LSSSs),the inherent non-uniformity and multidimensionality characteristics of earthquake ground motions should be properly taken into consideration.However,due to the limitations of available earthquake stations to record seismic rotational components,the effects of rocking and torsional earthquake components are commonly neglected in the seismic analyses of LSSSs.In this study,a newly developed method to extract the rocking and torsion components at any point along the area of a deployed dense array from the translational earthquake recordings is applied to obtain the rotational seismic inputs for a LSSS.The numerical model of an actual LSSS,the Dalian International Conference Center(DICC),is developed to study the influences of multi-support and multidimensional excitations on the seismic responses of LSSSs.The numerical results reveal that the non-uniformity and multidimensionality of ground motion input can considerably affect the dynamic response of the DICC.The specific degree of influence on the overall and local structural displacements,deformations and forces are comprehensively investigated and discussed.

Research on Construction Control Technology of Large-Span and Small Clear Distance Underpass High-Voltage Line Tunnel

Hanping tunnel is a control project of national highway 310 Dahejia to Qingshui highway project.It needs to cross a 330kV high-voltage transmission line under the condition of small clear distance,which requires high construction requirements.In view of the difficulties such as shallow buried depth of tunnel and small clear distance between tunnel and tower of high-voltage line,multiple excavation blasting method is adopted,and smooth blasting,charge quantity control and damping hole setting are comprehensively used to reduce the impact on the tower and structure of high-voltage line.In order to ensure the smooth progress of the project,the large-scale finite element analysis software is used to simulate the whole excavation project.The influence of the full-section method and the middle partition wall method(CD method)on the surrounding rock and the high-voltage electric tower is compared.It is found that the CD method can effectively control the displacement of the surrounding rock and the tower on it and the uneven settlement.

Distribution characteristics and the evolution law of excavation damage zone in the large-span transition section of high-speed railway tunnel based on microseismic monitoring

Purpose–The microseismic monitoring technique has great advantages on identifying the location,extent and the mechanism of damage process occurring in rock mass.This study aims to analyze distribution characteristics and the evolution law of excavation damage zone of surrounding rock based on microseismic monitoring data.Design/methodology/approach–In situ test using microseismic monitoring technique is carried out in the large-span transition tunnel of Badaling Great Wall Station of Beijing-Zhangjiakou high-speed railway.An intelligent microseismic monitoring system is built with symmetry monitoring point layout both on the mountain surface and inside the tunnel to achieve three-dimensional and all-round monitoring results.Findings–Microseismic events can be divided into high density area,medium density area and low density area according to the density distribution of microseismic events.The positions where the cumulative distribution frequencies of microseismic events are 60 and 80%are identified as the boundaries between high and medium density areas and between medium and low density areas,respectively.The high density area of microseismic events is regarded as the high excavation damage zone of surrounding rock,which is affected by the grade of surrounding rock and the span of tunnel.The prediction formulas for the depth of high excavation damage zone of surrounding rock at different tunnel positions are given considering these two parameters.The scale of the average moment magnitude parameters of microseismic events is adopted to describe the damage degree of surrounding rock.The strong positive correlation and multistage characteristics between the depth of excavation damage zone and deformation of surrounding rock are revealed.Based on the depth of high excavation damage zone of surrounding rock,the prestressed anchor cable(rod)is designed,and the safety of anchor cable(rod)design parameters is verified by the deformation results of surrounding rock.Originality/value–The research provides a new method to predict the surrounding rock damage zone of large-span tunnel and also provides a reference basis for design parameters of prestressed anchor cable(rod).

Grouping response method for equivalent static wind loads based on a modified LRC method

Wind loading is one of the most important loads for controlling the design of large-span roof structures. Equivalent static wind loads, which can generally aim at determining a specific response, are widely used by structural designers. A method for equivalent static wind loads applicable to multi-responses is proposed in this paper. A modified load- response-correlation （LRC） method corresponding to a particular peak response is presented, and the similarity algorithm implemented for the group response is described. The main idea of the algorithm is that two responses can be put into one group if the value of one response is close to that of the other response, when the structure is subjected to equivalent static wind loads aiming at the other response. Based on the modified LRC, the grouping response method is put forward to construct equivalent static wind loading. This technique can simultaneously reproduce peak responses for some grouped responses. To verify its computational accuracy, the method is applied to an actual large-span roof structure. Calculation results show that when the similarity of responses in the same group is high, equivalent static wind loads with high accuracy and reasonable magnitude of equivalent static wind distribution can be achieved.

Dynamic Reliability Assessment of Heavy Vehicle Crossing a Prototype Bridge Deck by Using Simulation Technology and Health Monitoring Data

Overloads of vehicle may cause damage to bridge structures,and how to assess the safety influence of heavy vehicles crossing the prototype bridge is one of the challenges.In this report,using a large amount of monitored data collected from the structural health monitoring system(SHMS)in service of the prototype bridge,of which the bridge type is large-span continuous rigid frame bridge,and adopting FEM simulation technique,we suggested a dynamic reliability assessment method in the report to assess the safety impact of heavy vehicles on the prototype bridge during operation.In the first place,by using the health monitored strain data,of which the selected monitored data time range is before the opening of traffic,the quasi dynamic reliability around the embedded sensor with no traffic load effects is obtained;then,with FEM technology,the FEM simulation model of one main span of the prototype bridge is built by using ANSYS software and then the dynamic reliability when the heavy vehicles crossing the prototype bridge corresponding to the middle-span web plate is comprehensively analyzed and discussed.At last,assuming that the main beam stress state change is in the stage of approximately linear elasticity under heavy vehicle loads impact,the authors got the impact level of heavy vehicles effects on the dynamic reliability of the prototype bridge.Based on a large number of field measured data,the dynamic reliability value calculated by our proposed methodology is more accurate.The method suggested in the paper can do good for not only the traffic management but also the damage analysis of bridges.

Seismic performance evaluation of large-span offshore cable-stayed bridges under non-uniform earthquake excitations including strain rate effect

This paper presents a novel and precise seismic performance evaluation method for large-span offshore cable-stayed(LSOCS)bridge by considering the strain rate effect of RC materials and the spatial variation effect of seafloor seismic motions. Threedimensional finite element(FE) model of a LSOCS bridge located in the southeast coast of China is constructed in the ABAQUS platform. The non-uniform ground motions at the offshore site beneath the bridge are stochastically simulated and used as seismic inputs. Moreover, a subroutine for considering the rate-dependent properties of RC materials in a fiber-based beamcolumn element model is developed to account for the strain rate effect of RC materials in the nonlinear time-history analysis.The numerical results indicate that seismic responses and fragilities of the LSOCS bridge are both considerably affected by the non-uniform seafloor seismic motions and strain rate effect. The seismic performance evaluation approach presented in this paper can provide vital support for earthquake resistant design of LSOCS bridges.

Green Construction of National Speed Skating Oval

1 Background As the basic principle of the world economy,environment,and social development,sustainable development is the focus of the international community today.In the Olympic Agenda 2020 published by the International Olympic Committee(IOC),sustainable development was officially listed as one of the core concepts of the Olympic Games.Since the beginning of the bid,the concept of ctathlete-centered,sustainable and economical”was proposed,which was highly consistent with the idea of the Olympic Agenda 2020.To implement the concept of holding“green”Olympic Games and meet the sustainability requirements of the IOC,the Organizing Committee of Beijing Winter Olympic Games issued a series of documents related to the sustainability of sports venues such as Sustainability Policies for 2022 Beijing Winter Olympic Games and Winter Paralympic Games,and strived to realize the sustainable development of sports venues in the whole life cycle of planning and design stage,construction stage,operation stage,and post-game utilization.