The Construction Process Simulation of a Large-Span Rhombic Space Truss Using FEM Analysis

2011 ◽  
Vol 368-373 ◽  
pp. 1101-1104
Author(s):  
Xu Yan ◽  
Tie Ying Li ◽  
Yun Jing Nie
Keyword(s):  
Fem Analysis ◽  
Construction Process ◽  
Large Span ◽  
Construction Design ◽  
Construction Methods ◽  
The North ◽  
Space Truss ◽  
Design Theories ◽  
The Stability ◽  
Space Trusses

With the developments of the design theories and the researches, the quantity and the technology of space truss systems in our country have reached the international leading level. In the meantime, the construction methods need to achieve even higher standard. In the article, the rhombic space truss roof of the north station building of Suzhou is selected as the research object. Each step of the sliding and unloading construction is simulated by FEM. The stability and rigidity of the truss are checked in detail. It gives an representative exsample for complicated construction design of large-span space trusses.

scholarly journals Research on Construction Methods for Ultralarge Y-Shaped Tunnel Sections

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Shiding Cao ◽  
Yongli Xie ◽  
Wei Tang ◽  
Wei Wang ◽  
Qianru Zhou ◽  
...  
Keyword(s):  
Stability Criterion ◽  
Abrupt Change ◽  
Internal Force ◽  
Special Method ◽  
Large Section ◽  
Large Span ◽  
Construction Methods ◽  
Excavation Process ◽  
Clear Distance ◽  
The Stability

Many problems are encountered in the construction of bifurcated tunnels due the abrupt change in section, small clear distance, and large section. Progress in the direction of tunnel construction is limited by the large-span section; therefore, a special method of construction that involves constructing a guiding tunnel first followed by reverse excavation was adopted to construct the large-span bifurcation section of the Liantang tunnel of Shenzhen Eastern Transit Expressway in China. The stability criterion of the surrounding rock of the middle wall in the section of multiple arch and small clear distance is studied by theoretical analysis, and the internal stress and corresponding ultimate strength of the middle wall under different buried depths and widths of the middle wall are calculated by the stability criterion. In this study, 3D finite-difference software was used to simulate the excavation process under forward and reverse excavation conditions. The results show that the displacement field and internal force field distribution are similar for both excavation methods, and the tunneling first and reverse excavation construction method is safe and reliable.

scholarly journals Dynamic Numerical Analysis of Displacement Restraining Effect of Inclined Earth-Retaining Structure during Embankment Construction

2019 ◽  
Vol 9 (11) ◽  
pp. 2213 ◽  
Author(s):  
Su-Won Son ◽  
Minsu Seo ◽  
Jong-Chul Im ◽  
Jae-Won Yoo
Keyword(s):  
Numerical Analysis ◽  
Maximum Stress ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Field Tests ◽  
Front Wall ◽  
Construction Process ◽  
Construction Methods ◽  
Excavation Process ◽  
The Stability

Retaining walls are generally used for temporary installations during the excavation process of a construction project. They are also utilized to construct embankments in order to extend a railway facility. In this case, a retaining wall is installed during the construction process and contributes to the resistance of large amounts of stress, including the railway load. However, it is generally difficult to retain walls to maintain their stability. Therefore, alternative construction methods, such as the use of an inclined earth-retaining wall, have been utilized to suppress the lateral displacement. The stability is verified in advance through field tests; however, the maximum stress acting on the railway is thought to be the concentrated railway load. In this study, a two-dimensional numerical analysis was conducted by changing the railway load to a dynamic load. The analysis was applied according to the number of H-piles of the same length (10 m) when only the front wall was installed and when a back support was also applied. It was determined that the lateral displacement of the latter case is smaller than that of the former, whereas the resistance to dynamic loading of the former case is greater.

scholarly journals Study on Identification of Construction Method for Ultra-Large-Span Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xu Chongbang ◽  
Qin Youlin
Keyword(s):  
Rock Strength ◽  
Construction Method ◽  
Surrounding Rock ◽  
Orthogonal Test ◽  
Tunnel Construction ◽  
Test Model ◽  
Large Span ◽  
Construction Methods ◽  
The Stability

Although the determination of tunnel construction methods is extremely critical for the construction of ultra-large-span tunnels, the determination of construction methods is still at a qualitative level, which relies on the engineering experience of on-site technicians and lacks rigorous and systematic theoretical basis and technical standards. By means of orthogonal test method, the proper construction method was established for the deep-buried ultra-large-span tunnel where the tunnel excavation span, tunnel surrounding rock strength, and rock integrity coefficient were set as the main control factors. The stability of tunnel surrounding rock under various test conditions was quantified according to the plastic zone properties calculated by the three-factor and five-level orthogonal test model. Meanwhile, the macro form and quantitative method of test combinations under different levels of various factors were proposed to obtain the influence of each factor on the stability of tunnel surrounding rock, and thus the functional relations between various factors and tunnel stability were obtained. On this basis, the identification and the criterion of the ultra-large-span tunnel construction method were established, which can quantitatively reflect the contribution of excavation span of the tunnel, the number of lateral drifts in cross section, surrounding rock strength, and rock integrity coefficient to surrounding rock stability of the tunnel. The construction method calculation results of the Malin tunnel, a practical underground project, are obtained according to the orthogonal test model calculation. Based on the method, Malin tunnel can be constructed safely and efficiently. The research results could provide the theoretical basis for the identification and selection of construction method for ultra-large-span tunnel.

scholarly journals Optimization Analysis of Construction Scheme for Large-Span Highway Tunnel Under Complex Conditions

2018 ◽  
Vol 64 (4) ◽  
pp. 55-68
Author(s):  
Jiao Pengfei ◽  
Xiao Zhang ◽  
Xinzhi Li ◽  
Bei Jiang ◽  
Bohong Liu ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Three Dimensional ◽  
Simulation Software ◽  
Construction Process ◽  
Diagram Method ◽  
Deformation Control ◽  
Large Span ◽  
Construction Methods ◽  
Rock Stability ◽  
Construction Scheme

AbstractThe construction process of the tunnel ground deformation regularity of surrounding rock, stability, deformation control of tunnel surface based on the requirements, combined with the characteristics of shallow tunnel with large-span. Used three-dimensional numerical simulation software, established a dynamic tunnel analysis program to simulate the construction process of center cross-diagram method and double sidewall drift method. Based on the stratum deformation, supporting force and analysis of plastic zone distribution, comparative analysis of engineering adaptability of different construction methods from the construction process and construction mechanics, get optimization tunnel construction scheme.

A New Reinforcement Measure Suited for Space Truss with No-Fire Operation

2014 ◽  
Vol 919-921 ◽  
pp. 401-405
Author(s):  
Zuo Yun Mei ◽  
Chuan Qing Liu ◽  
Xing Mi ◽  
Ping Wu
Keyword(s):  
Element Model ◽  
High Yield ◽  
Nonlinear Analyses ◽  
High Yield Strength ◽  
Shell Elements ◽  
Gas Stations ◽  
Space Truss ◽  
Reinforcement Measure ◽  
Space Trusses ◽  
Elastic Stage

A new reinforcement measure with no-fire operation is presented, which is very suitable for space trusses which are located in gas stations. A finite element model (FEM) is presented with shell elements and multipoint constraint elements. With this FEM, nonlinear analyses are carried out. Analytical results show that integral failure of reinforced pipe is caused by yielding of original pipe inside. So it is not necessary to reinforce original pipe using steel pipe bonded outside with high yield strength. With the increase of length of bonded pipe outside, loading according to elastic stage and ultimate bearing loading increase, it is clear that the length of bonded pipe outside is an important factor which influences the bearing capacity.

Assessing the temporal reliability of rhythm metrics

2011 ◽  
Vol 41 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Rachael-Anne Knight
Keyword(s):  
Current Paper ◽  
Empirical Measure ◽  
The Sun ◽  
British English ◽  
The North ◽  
North Wind ◽  
The Stability ◽  
Current Popularity ◽  
Temporal Reliability

Despite the current popularity of rhythm metrics, there has been relatively little work aimed at establishing their validity or reliability, important characteristics of any empirical measure. The current paper focuses on the stability, or temporal reliability, of rhythm metrics by establishing if they give consistent results for the same speakers, in the same task, on successive occasions. Four speakers of Southern British English were recorded reading ‘The North Wind and the Sun’ (NWS) passage on three consecutive days. Results indicated that some measures correlate more highly across time than others, and the choice of a measure that is both reliable and valid is discussed. It is suggested that the metric that best fits these criteria is formulated in terms of the proportion of vowels within an utterance (%V).

Yield Design of the Reinforced Embankment

2011 ◽  
Vol 368-373 ◽  
pp. 2804-2807
Author(s):  
Bing Zhang ◽  
Xiao Mou Wang
Keyword(s):  
Upper Bound ◽  
Design Approach ◽  
Stability Factor ◽  
Multiphase Model ◽  
Construction Process ◽  
Backfill Soil ◽  
Geotechnical Structures ◽  
The Stability ◽  
Kinematic Approach

A frequently used technique for improving the performance of geotechnical structures consists in incorporating into the backfill soil, during the construction process, regularly spaced thin reinforcing inclusions, called geotextile, geomembranes or geogrids. The stability of embankment, stabilized by reinforcing membranes, is investigated by means of a multiphase model developed in the framework of the yield design approach. By means of the kinematic approach, leading to upper bound estimates for the stability factor of the structure.

Bridge bearing solutions that facilitate quick and efficient bearing installation and bridge construction

2019 ◽  
Author(s):  
Simon Hoffmann ◽  
Amit Kutumbale ◽  
Danilo Della Ca'
Keyword(s):  
Load Distribution ◽  
Construction Method ◽  
Construction Process ◽  
Vital Function ◽  
Bridge Construction ◽  
Construction Methods ◽  
Efficient Construction ◽  
Critical Components ◽  
Bridge Bearing ◽  
Segmental Bridge

<p>A bridge’s bearings, arguably its most critical components, perform a vital function throughout the bridge’s service life, but the bearings used can also have a significant impact on the bridge construction process. Suitably designed adjustable bearings are an integral part of the incremental launch method of bridge construction, for instance, which can be a very efficient construction method. Adjustable bearings may also support other bridge construction methods, such as segmental bridge construction, where fixities/freedoms that applied during the construction phase require to be changed before the bridge enters service. Lifting bearings, the height of which can be increased, may enable a lack of precision in the structure to be tolerated, and measuring bearings may enable load distribution during bridge construction to be verified, where this is required by the construction method. Design features of otherwise standard bearings that support quick and high-quality installation can also contribute towards the efficiency of the overall bridge construction process, as can the use of bearing designs which minimize bearing size. Bearing solutions and features that facilitate bearing installation and bridge construction in ways such as these are described.</p>

Sensitivity of Composite and Non-Composite Space Trusses to Member Loss

1994 ◽  
Vol 9 (2) ◽  
pp. 107-119 ◽  
Author(s):  
Ahmed El-Sheikh
Keyword(s):  
Double Layer ◽  
Concrete Slab ◽  
Noticeable Effect ◽  
Composite Action ◽  
Space Truss ◽  
Space Trusses ◽  
Loss Factors

Since double layer space trusses have typically a large number of redundant members, it is frequently assumed that they are quite safe as the loss of one or more members can be accommodated without any noticeable effect on truss overall behaviour. The present study shows that every truss includes a number of critical members, the loss of any of which would cause force distributions that could lead to an overall premature collapse. The sensitivity of space trusses to member loss is clearly identified. The composite action between a top concrete slab and a space truss is also introduced as a means to control truss sensitivity to member loss. Factors that affect this sensitivity such as the truss supporting conditions are also investigated.

Construction Monitoring Technology Research on Large-Span V Structure Tied Arch Bridge

2013 ◽  
Vol 351-352 ◽  
pp. 1240-1243 ◽  
Author(s):  
Ting Yin ◽  
Wei Zhang ◽  
Yan Bo Zhao ◽  
Xiao Long Sun
Keyword(s):  
Actual State ◽  
Construction Process ◽  
Bridge Construction ◽  
Monitoring Point ◽  
Monitoring Technology ◽  
Construction Monitoring ◽  
Arch Bridge ◽  
Large Span ◽  
Long Span ◽  
Tied Arch Bridge

Large-span V structure tied arch bridge structure system is complex. In order to make the actual state of the bridge into the ideal state of maximum close to the design, we must make real-time monitoring in the key parts of the structure, and adjust to the design of the data by analysis calculated, to ensure the safety and reliability of arch bridge in the course of construction and into stress after the completed bridge. Combined with the construction monitoring of the main Xinglong Bridge on Si River, this paper introduces the main bridge construction process measurement a preliminary study on the large span V configuration basket tied arch bridge construction monitoring technology. Based on the construction monitoring of Xinglong Bridge on Si River, this paper introduces the main contents and methods of monitoring point location, monitoring control of construction process, and discussed the construction monitoring technology of long-span X-style tied arch bridge V structure.

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