Structural robustness of long-span cable-supported bridges segmented by zipper-stoppers to prevent progressive collapse

2018 ◽  
Author(s):  
Mohammad Shoghijavan ◽  
Uwe Starossek
Keyword(s):  
Analytical Approach ◽  
Good Accuracy ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Structural System ◽  
Structural Behaviour ◽  
Load Bearing Capacity ◽  
Approximation Function ◽  
Long Span ◽  
Bridge Model

<p>This paper investigates the structural behaviour of a long-span cable-supported bridge segmented by zipper-stoppers after the sudden rupture of some of its cables. Increasing the robustness of the structural system through segmentation is a possible approach to prevent progressive collapse in bridges due to cable failure. In this concept, zipper-stoppers, at the segment borders, are strong components with the multiple of the load bearing capacity of usual members and are designed to arrest a zipper-like collapse in the segment where the initial damage occurred. For finding the “stress increase ratio” of the zipper-stopper, an analytical approach based on differential equations of the system will be used. Then, an approximation function for a simplified bridge model in a cable-loss scenario will be derived. The proposed approximation function has been checked by numerical models, and its good accuracy has been proven.</p>

Seismic Testing of a Long-Span Concrete Filled Steel Tubular Arch Bridge

2010 ◽  
Vol 456 ◽  
pp. 89-102 ◽  
Author(s):  
Wei Ming Yan ◽  
Yong Li ◽  
Yan Jiang Chen
Keyword(s):  
Dynamic Performance ◽  
Internal Force ◽  
Shaking Table ◽  
Structural System ◽  
Arch Bridge ◽  
Seismic Testing ◽  
Response Characteristics ◽  
Long Span ◽  
Bridge Model ◽  
Cfst Arch Bridge

Long-span bridges are always a multi-support structural system, and seismic ground motion can vary significantly over distances comparable to the length of such kind of bridges, so it’s difficult to carry out shaking table tests because of the restriction of the dimension and amount of shaking tables. This paper discusses the multiple sub-table cordwood system is used to conduct a study on the seismic testing of a three-span irregular Concrete filled steel tubular (CFST) arch bridge with the objective of investigating the dynamic performance of the bridge under spatial earthquake motions. The development and testing of the bridge model and selected experimental results are discussed then. The seismic response and response characteristics of acceleration, displacement, internal force, and strain of the structure under earthquake excitations are gained, which can provide test data and basis to evaluate the seismic performance of this CFST arch bridge or other similar structural system design.

Simulating Post Punching Behaviour of RC Slab-Column Connections Using a Micro Model

2016 ◽  
Vol 846 ◽  
pp. 231-236
Author(s):  
Hui Zhong Xue ◽  
Hong Guan ◽  
Xin Zheng Lu ◽  
Yi Li
Keyword(s):  
Numerical Model ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Structural Response ◽  
Calibration Method ◽  
Failure Criteria ◽  
Micro Model ◽  
Structural Behaviour ◽  
Flat Plates ◽  
Rc Slab

Punching shear is a common failure mode occurring at the slab-column connection region of a reinforced concrete (RC) flat plate. Progressive collapse of RC flat plates poses a significant scientific question on the post punching behaviour of such a structural system. The challenge lies in the complex interactions amongst various internal actions including large unbalanced moments and shear forces. Existing numerical models are unable to differentiate the influence of each individual action within the connection region after punching occurs. Therefore, a new numerical model is required to model these actions individually as well as to evaluate their interrelationships. This paper thus aims to propose a numerical method to investigate the structural response of RC slab-column connections by using a micro model, based on a representative post punching failure experiment. In the micro model, concrete is simulated using solid elements whilst the reinforcement is modelled with truss elements. In this micro model, the constitutive laws and failure criteria of materials play a crucial role in describing the model’s structural behaviour. A typical structural response is discussed and a calibration method is established. Ultimately this study is expected to facilitate the development of an effective, yet simplified numerical model for future progressive collapse simulation of slab-column connections.

scholarly journals Experimental Investigation of the Maximum Punching Resistance of Slab-Column Connections

2018 ◽  
Vol 26 (3) ◽  
pp. 22-28 ◽  
Author(s):  
Jaroslav Halvoník ◽  
Lucia Majtanová
Keyword(s):  
Experimental Investigation ◽  
Progressive Collapse ◽  
Transverse Reinforcement ◽  
Test Results ◽  
Structural System ◽  
Structural Behaviour ◽  
Shear Forces ◽  
Flat Slab ◽  
Direct Verification ◽  
Flat Slabs

Abstract Flat slabs represent a structural system with a typical concentration of shear forces near the vicinity of its local supports. A possible failure from punching is a dangerous phenomenon due to the brittleness and possible progressive collapse of a whole structure. An improvement in the structural behaviour of a slab-column connection provides transverse reinforcement. The amount of this reinforcement and thus its contribution to the resistance against punching has a limit, which is represented by the maximum punching capacity. This capacity can be assessed using the kmax factor or by direct verification of the strut capacity. The article deals with the results of a test campaign carried out on flat slab specimens with their transverse reinforcements designed in such a way that the crushing of the struts is the governing mode of any failure. The test results obtained allowed for an evaluation of the kmax factors and provide an answer as to whether it is possible to cover failures due to the crushing of struts by this factor.

scholarly journals Parametric Analysis of the Shear Lag Effect in Tube Structural Systems of Tall Buildings

2020 ◽  
Vol 11 (1) ◽  
pp. 278
Author(s):  
Ivan Hafner ◽  
Anđelko Vlašić ◽  
Tomislav Kišiček ◽  
Tvrtko Renić
Keyword(s):  
Parametric Analysis ◽  
Numerical Models ◽  
Tall Buildings ◽  
Structural Systems ◽  
Structural Elements ◽  
Structural System ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Lag Effect ◽  
Secondary Structural Elements

Horizontal loads such as earthquake and wind are considered dominant loads for the design of tall buildings. One of the most efficient structural systems in this regard is the tube structural system. Even though such systems have a high resistance when it comes to horizontal loads, the shear lag effect that is characterized by an incomplete and uneven activation of vertical elements may cause a series of problems such as the deformation of internal panels and secondary structural elements, which cumulatively grow with the height of the building. In this paper, the shear lag effect in a typical tube structure will be observed and analyzed on a series of different numerical models. A parametric analysis will be conducted with a great number of variations in the structural elements and building layout, for the purpose of giving recommendations for an optimal design of a tube structural system.

Super-long span bridge aerodynamics: on-going results of the TG3.1 benchmark test – Step 1.2

2019 ◽  
Author(s):  
Giorgio Diana ◽  
Stoyan Stoyanoff ◽  
Andrew Allsop ◽  
Luca Amerio ◽  
Tommaso Argentini ◽  
...  
Keyword(s):  
Numerical Models ◽  
Experimental Tests ◽  
Numerical Comparison ◽  
Aeroelastic Stability ◽  
Turbulent Wind ◽  
Long Span Bridges ◽  
Buffeting Response ◽  
Long Span ◽  
Long Span Bridge ◽  
Sectional Model

<p>This paper is part of a series of publications aimed at the divulgation of the results of the 3-step benchmark proposed by the IABSE Task Group 3.1 to define reference results for the validation of the software that simulate the aeroelastic stability and the response to the turbulent wind of super-long span bridges. Step 1 is a numerical comparison of different numerical models both a sectional model (Step 1.1) and a full bridge (Step 1.2) are studied. Step 2 will be the comparison of predicted results and experimental tests in wind tunnel. Step 3 will be a comparison against full scale measurements.</p><p>The results of Step 1.1 related to the response of a sectional model were presented to the last IABSE Symposium in Nantes 2018. In this paper, the results of Step 1.2 related to the response long-span full bridge are presented in this paper both in terms of aeroelastic stability and buffeting response, comparing the results coming from several TG members.</p>

Blast Vulnerability Assessment of Road Tunnels with Reinforced Concrete Liners

2018 ◽  
Vol 2672 (41) ◽  
pp. 156-164 ◽  
Author(s):  
Fengtao Bai ◽  
Qi Guo ◽  
Kyle Root ◽  
Clay Naito ◽  
Spencer Quiel
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Transportation Network ◽  
Computational Effort ◽  
Public Access ◽  
Tunnel Current ◽  
Circular Tunnel ◽  
Inflection Points ◽  
Road Tunnels

Tunnels are a critical component of our transportation infrastructure, and unexpected damage to a tunnel can significantly and adversely impact the functionality of a transportation network. Tunnel systems are vulnerable to potential threats of intentional and accidental blast events because of their relatively unrestricted public access. These events can lead to spalling and breach of the tunnel liner which, depending on the surrounding media, can result in local damage and progressive collapse of the tunnel. Current approaches for evaluating blast-induced damage to a tunnel liner either require significant computational effort or oversimplification such that accurate spatial distributions of damage cannot be obtained. This study presents an effective approach to predict and map the damage to a reinforced concrete liner of a roadway tunnel from various explosive threat sizes and tunnel geometries. A literature review of existing studies is conducted, and potential scenarios of blast events are examined with varying charge position and size. Rectangular, horseshoe, and circular tunnel geometries, each with the same traffic throughput, are evaluated. An efficient analytical approach to determine the spatial distribution of blast-induced spall and breach damage is presented and shows good agreement with numerical models analyzed in LS-DYNA. The proposed approach is then used to examine the relationship between increasing blast hazard intensity and the extent of spall and breach damage. Inflection points in this relationship can be used to identify hazard levels at which a progressive collapse evaluation would be warranted.

scholarly journals History, observation and mathematical models in the seismic analysis of the Valadier abutment area in the Colosseum

1995 ◽  
Vol 38 (5-6) ◽  
Author(s):  
G. Croci ◽  
D. D'Ayala ◽  
R. Liburdi
Keyword(s):  
Mathematical Models ◽  
Seismic Analysis ◽  
Numerical Models ◽  
Time History ◽  
Historical Records ◽  
Direct Integration ◽  
Structural Behaviour ◽  
Seismic Behaviour ◽  
Before And After ◽  
Xix Century

The present work aimed to outline the need to investigate different fields of research to interpret the structural behaviour of a monument as complex as the Colosseum. It is shown how defining the numerical models first. then refining them, followed by interpretation of results. is strictly linked with the inforination gathered from historical records and observation of the ~nonumenta s it is today. The study is confined to the area of the Valadier abutment. analysing its state and its seismic behaviour before and after the XIX century restoration using different ilumerical tools, from the elastic modal analysis to the non linear step by step time history direct integration. The procedure comparati\ely evaluates the reliability in the interpretation of the results and identifies future lines or research.

RESISTANCE OF THE PRECAST - CAST-IN-SITU REINFORCED CONCRETE FRAMES OF CIVIL BUILDINGS UNDER SPECIAL EMERGENCY IMPACT

2021 ◽  
Vol 96 (4) ◽  
pp. 45-55
Author(s):  
P.A. KORENKOV ◽  
◽  
S.S. FEDOROV ◽  
Keyword(s):  
Thermal Protection ◽  
Progressive Collapse ◽  
Structural System ◽  
Concrete Frames ◽  
Limiting State ◽  
Space Planning ◽  
Numerical Studies ◽  
Design Loads ◽  
Multi Level

The paper obtained and analyzed the results of a numerical analysis of the survivability of a new industrial structural system of residential and public buildings that meets modern requirements for protection against progressive collapse, improved space-planning, architectural and thermal protection solutions. The presence of a significant number of enterprises with technological lines for the production of structures for large-panel housing construction and their market share, combined with a number of disadvantages of the applied technical and space-planning solutions, indicates the need to modernize these enterprises in order to produce products that meet modern requirements. The purpose of this study was to qualitatively and quantitatively study the parameters of the stress-strain state of the industrial structural system of civil buildings proposed by the authors with increased resistance to progressive collapse, the production of which would not require expensive modernization of the construction industry enterprises. On the basis of multi-level design schemes, an algorithm for calculating such a system for a special emergency effect is proposed. Numerical studies have established the compliance of the developed structural system with the requirements of a special limiting state under design loads and emergency effects caused by the sudden removal of a vertical load-bearing element.

Numerical investigation on load transfer mechanism of bonded post-tensioned concrete beam-column substructures against progressive collapse

2020 ◽  
pp. 136943322098165
Author(s):  
Kai Qian ◽  
Hai-Ning Hu ◽  
Yun-Hao Weng ◽  
Xiao-Fang Deng ◽  
Ting Huang
Keyword(s):  
Prestressed Concrete ◽  
Load Transfer ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Load Resistance ◽  
Catenary Action ◽  
Parabolic Profile ◽  
Arch Action ◽  
Column Removal Scenario ◽  
Post Tensioned

This paper presents the high-fidelity finite-element-based numerical models for modeling the behavior of prestressed concrete (PC) beam-column substructures to resist progressive collapse under column removal scenario. After careful calibration against data, the validated numerical models are further employed to shed light on the influence of bonded post-tensioned tendons (BPT) with a parabolic profile on the load transfer mechanisms of PC frames against progressive collapse. The effects of parameters, including initial effective prestress, profile of tendon and lateral constraint stiffness at the beam ends, are also investigated. The study shows that, due to the presence of prestressed tendons, the mobilization of compressive arch action in the beam at small deflections demands stronger lateral constraints, and the ultimate load resistance of PC beam-column substructures depends on combined catenary action from non-prestressed reinforcement and BPT at large deflections. For a given constraint stiffness, the initial effective prestress of BPT has less significant effect on the overall structural behavior. For prestressed tendon, a straight profile usually employed in structural strengthening can improve the initial structural stiffness and yield strength, but is less effective in enhancing the ultimate resistance against progressive collapse than the parabolic profile.

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