Concrete Arch Structure Research Articles

Numerical simulation on the load-bearing capacity of CFRP-strengthened concrete arches

To investigate the bearing capacity of concrete structures strengthened by carbon fiber reinforced composite (CFRP), this study conducted numerical simulation research on seven CFRP-strengthened concrete arch structures with five different strengthening schemes. The finite element model was established by HYPERMESH, the simulation results were compared with the experimental results to verify the accuracy of the model. Based on this, the interfacial bonding performance of concrete and CFRP under different strengthening schemes was analyzed, and the static damage mode of the reinforced concrete arch structure was revealed. The results indicate that the application of CFRP to the surface of a concrete arch will increase the linear segmental stiffness, cracking load, and ultimate load of the structure. The five strengthening schemes in this paper provide enhancements ranging from 2.9 % to 57.6 % for concrete arch cracking loads, from 3.3 % to 14.7 % for ultimate loads, and from 1.1 % to 17.6 % for stiffness. If both the inner and outer sides are strengthened with CFRP, the ultimate bearing capacity of the arch structure can be significantly enhanced. Circumferential wrapping of CFRP can delay the concrete cracking and further enhance the bearing capacity of the arch, and the strengthening effect can be maximized. This study can provide a valuable reference for the strengthening of old concrete arch structures and the construction of newly assembled arch tunnels.

Experimental study on the anti-blast performance of polyurea reinforced concrete arch structures

In order to study the anti-blast performance of the concrete arch structure strengthened by polyurea, the bottom (inner side) of the concrete arch structure is reinforced by coating polyurea with different thicknesses, which conducts anti-blast tests on the composite arch structure under the blast load of TNT in the air. The test recorded the dynamic response data of arch structure under the action of blast load, including reflected pressure at the vault, strain of the bars and deformation of arches. In order to further evaluate the damage of the arch under blast load, quasi-static loading tests were carried out on the residual bearing capacity of the damaged arch structures. Through the analysis of the damage to the arch structure after blast load, this paper clarifies the reinforcement mechanism of polyurea on concrete arch structure. Compared with the reinforced concrete(RC)arch structure, the damage and deformation of the composite arch can be controlled by coating polyurea, thus further improving the structural integrity of the composite arch after blast load. The experimental results show that anti-blast capacity and ductility characteristics of the arch strengthened by polyurea have improved than those of RC arch structure, and the overall mechanical properties of the composite arch structure have strenthened with the increase of the polyurea reinforced thickness. By adopting the rational design of polyurea reinforcement layer and concrete arch structure, a protective structure with better anti-blast performance can be manufactured.

An integrated method of topological optimization and path design for 3D concrete printing

As an advanced construction technology, 3D concrete printing (3DCP) has the advantage of high manufacturing freedom for various freeform structures. The digital design of 3D printing using topology optimization contributes to obtaining the maximum performance potential from manufactured structures. However, most digitally designed structures obtained by topology optimization cannot be directly manufactured using 3DCP owing to various manufacturing constraints that have not yet been considered in the design process. This paper presents an integrated design method for 3DCP by incorporating extrusion-based manufacturing characteristics into the topology optimization algorithm. Topological optimization is based on the solid isotropic material with penalization (SIMP) method owing to its ease of adaptation to multiple constraints. During the optimization iteration, the manufacturing characteristics of nozzle size and path continuity are considered as the design requirements of 3D printed structures to achieve high-quality manufacturing by using intermittent interruption of topology optimization to modify the design variables. Meanwhile, the anisotropic behaviors of material constraints and the volume and Tsai-Wu criterion of design constraints are introduced to obtain the desired mechanical performance with lightweight designs. Moreover, the number of closed regions and overhang angle controls are incorporated to ensure the global path continuity and stable stacking of optimized 3D structures. A concrete arch structure is 3D printed to validate the proposed integrated method, and the removal of breakpoints and short paths and complete filling rate are demonstrated. The integrated method facilitates the engineering application of 3DCP in a high-efficiency and high-quality manner.

Anti-Blast Performance of Polyurea-Coated Concrete Arch Structures

With the increasing number of violent terrorist attacks around the world, it is quite a common to improve the anti-blast performance of structures by reinforcing the exterior of the structure. In order to explore the dynamic performance of polyurea reinforced concrete arch structures, a three-dimensional finite element model was established by LS-DYNA software in this paper. Under the condition of ensuring the validity of the simulation model, the dynamic response of the arch structure under the blast load is investigated. Deflection and vibration of the structure under different reinforcement models are discussed. The optimum thickness of reinforcement (approximately 5 mm) and the strengthening method for the model were found by deformation analysis. The vibration analysis shows that the vibration damping effect of the sandwich arch structure is relatively excellent, but increasing the thickness and number of layers of the polyurea does not necessarily achieve a better vibration damping function for the structure. By reasonable design of the polyurea reinforcement layer and concrete arch structure, a protective structure with excellent performance of anti-blast and vibration damping can be created. Polyurea can be used as a new form of reinforcement in practical applications.

Dynamic Responses of Blast-Loaded Shallow Buried Concrete Arches Strengthened with BFRP Bars.

This paper proposes a prefabricated basalt fiber reinforced polymer (BFRP) bars reinforcement of a concrete arch structure with superior performance in the field of protection engineering. To study the anti-blast performance of the shallow-buried BFRP bars concrete arch (BBCA), a multi-parameter comparative analysis was conducted employing the LS-DYNA numerical method, which was verified by the results of the field explosion experiments. By analyzing the pressure, displacement, acceleration of the arch, and the strain of the BFRP bars, the dynamic response of the arch was obtained. This study showed that BFRP bars could significantly optimize the dynamic responses of blast-loaded concrete arches. The damage of exploded BBCA was divided into five levels: no damage, slight damage, obvious damage, severe damage, and collapse. BFRP bars could effectively mitigate the degree of damage of shallow-buried underground protective arch structures under the explosive loads. According to the research results, it was feasible for BFRP bars to be used in the construction of shallow buried concrete protective arch structures, especially in the coastal environments.

The Evolution and Research Progress of the Arch Structure

With its unique structural system and rich history and culture, wooden structure bucket arch has become a typical component of Chinese wooden structure architecture. Based on the analysis of the shortcomings of wooden structure, with the emergence of modern antique buildings, wooden structure bucket arch is gradually replaced by prefabricated concrete structure bucket arch. This paper introduces the development and evolution of the bucket arch structure, analyses the research progress of the bucket arch structure, puts forward the advantages and disadvantages of the wooden structure and the concrete structure, and defines the research direction of the prefabricated concrete bucket arch structure.

Construction of a concrete segmental arch bridge over a railway

This paper describes the modelling of the behaviour of a large precast concrete segmental arch structure during construction over a main line railway. The main aim of the modelling was to accurately predict the deflections of the segmental arch during construction and to set trigger levels to prevent another failure similar to that which occurred at Gerrards Cross, UK. The failure at Gerrards Cross, reported in 2005, demonstrated the importance of controlling the backfill and carefully controlling and monitoring the deflections of the arch during construction. To enable accurate predictions, finite-difference analysis of the precast segmental structure was utilised, which takes account of the soil–structure interaction effects covering structure and soil stiffness. Many sensitivity analyses were necessary to predict lower and upper bounds using predominant parameters that influenced the behaviour and included the movement of the arches on the piled foundations. Observations taken on site of movements of the arch during construction showed that actual deflections matched the predicted movements to a very high degree.

Spalling in concrete arches subjected to shock wave and CFRP strengthening effect

The purpose of the present study is to put forward an innovative method to improve dynamic response behaviors of protective concrete arches subjected to blast load. To achieve this goal eight arches were made, of which six were strengthened with carbon fiber reinforced polymers (CFRPs) on the intrados. Field explosion experiments were designed and carried out to reveal the strengthening effects of different CFRP strengthening schemes. The dynamic structural responses of the tested arches were recorded through linear variable differential transformers (LVDTs) and pressure sensors. The results of the experiments, such as the distribution of concrete cracks and the debonding length of the CFRP strips, indicate that CFRPs are effective in reducing concrete cracking and spalling of the protective arches, and that the fully-bonding method is significantly more effective than the partially-bonding method. Meanwhile, when the scaled standoff distance decreases, the strengthened arches experience failures ranging from ductile cracking to dynamic spalling. Simplified analysis models are proposed to estimate the equivalent static load and to reveal the protective mechanism of the CFRP strengthening. The research confirms that by using the CFRP bonding technique, an efficiently protective concrete arch structure with excellent anti-explosion performance could be constructed.

More than a Bridge

When the Centerway Bridge—a seven-span concrete arch structure linking the southern and northern sections of Corning, New York—was deemed too deteriorated to carry even pedestrians and bicyclists, demolition seemed inevitable. But community outcry spurred the city and its engineering consultants to look deeper—literally as well as figuratively—to determine how the bridge could be saved and returned to service as not only a river crossing but also a dynamic civic park.

Load Carrying Capacity of Reinforced Concrete Arch Structure Considering Loading Condition

The design guideline of R/C shell has not been established in Japan because of several technical difficulties. It is possible to analyze the strength of R/C shell by means of the finite element method but precise experiments are required to verify the analytical results reliably. Therefore, this research conducted the loading test of R/C arch as the basic form of R/C shell. Two kinds of R/C arch without initial imperfection were set under several loading conditions and were analyzed the load carrying characteristics of R/C arch with idealized pinned support. Consequently, it became clear that the axial stress and flexural stress of R/C arch depend on the shape of R/C arch and these combinations strongly influenced the deformation behavior and the strength characteristics of R/C arch.

Numerical Analysis of Underground Concrete Arch Structure Strengthened with Near-Surface Bonded CFRP Strips

To strengthen underground arch structure, the method with near-surface bonded carbon fiber reinforced polymer (CFRP) strips is proposed. A nonlinear finite element program is built to analyze concrete arch structure strengthened with CFRP. Factors that influence the strengthening effect are discussed. After arch strengthened with near-surface bonded CFRP strips, the cracking load, the yield load and the ultimate load has been greatly improved, the stiffness has also been greatly improved. The bearing capacity and the stiffness of arch structure increase with the layer quantity of CFRP increasing, increase with the strip quantity of CFRP in units increases. In the condition of the layer quantity and the strip quantity of CFRP being identical, the increasing ratio of load decreases with the reinforcement ratio increasing.

Comparative Analysis of Several Construction Scheme of a Large-Sized Tie-Arch Aqueduct

An aqueduct of larger-span prestressed concrete arch structure for river diversion project is located in coastal areas, and raises difficult questions on deformation and stability control of the construction process due to greater wind load and poor soil. Due to the limited width of bracket erection, this paper put forward five possible construction schemes, and does the comparative analysis using three-dimensional finite element program, and gets the economic and reasonable one. Finally conduct a pressure test after the bracket erection, and verify the analysis results using measured stress and deformation data.

Blast analysis of concrete arch structures for FRP retrofitting design

Fiber Reinforced Polymer (FRP) is widely used for retrofitting concrete structures for various purposes. Especially, for the retrofitting of concrete structures subjected to blast loads, FRP is proven to be a very effective retrofitting material. However, a systematic design procedure to implement FRP for concrete structure retrofitting against blast loads does not exist currently. In addition, in case of concrete structures with inarticulate geometrical boundary conditions such as arch structures, an effective analysis technique is needed to obtain reliable results based on minimal analytical assumptions. Therefore, in this study, a systematic and efficient blast analysis procedure for FRP retrofitting design of concrete arch structure is suggested. The procedure is composed of three sequential parts of preliminary analysis, breach and debris analysis, and retrofit-material analysis. Based on the suggested procedure, blast analyses are carried out by using explicit code, LS-DYNA. The study results are discussed in detail.

Damage analysis and numerical simulation for failure process of a reinforced concrete arch structure

This work focuses on the implementation of damage mechanics model to explain and understand failure mechanisms of the concrete structures. A tensorial damage theory and an isotropic application to the arch ribs of a real bridge are presented. Two reinforced concrete arch ribs of a 28 year old bridge has been removed from the field to the laboratory. They were loaded up to failure in order to study the remaining strength of the structure. The damage model involves three independent parameters for simulating the damage behaviors of the concrete material. The damage theory—additional load—finite element method is developed to simulate numerically the failure process of the RC structures based on the proposed damage model. The predicted displacements, strains and failure mode of the RC arch are good agreement with the experimental results. The values of the three material parameters that describe the damage characteristics of concrete were obtained. The numerical calculations revealed the interested behaviors of concrete in a damaging process. The proposed damage model can be used effectively to describe the damage and fracture behaviors of concrete.

Somerset County Bridge: A Precast Replacement Solution

Precast concrete played a prominent role in constructing the new Somerset County Bridge - a distinguished precast, reinforced concrete arch structure, which replaced an old deteriorated highway bridge in Somerville, New Jersey. The new crossing comprises two precast, reinforced concrete curved members to form a 60 ft (18.3 m) clear span with a 9 ft 6 in. (2.90 m) rise and a 50 ft (15.2 m) width. The overall length of the structure, including retaining walls, is 90 ft (27.4 m). The bridge incorporates 18 precast panel components that mimic the look of stone as well as 120 precast balusters made with white concrete. The precast concept used in this project is being advocated by county officials as an example for other damaged or new arch bridges in a similar span range.

Wisconsin Avenue Viaduct Design-Construction Highlights

The new Wisconsin Avenue Viaduct in Milwaukee, Wisconsin, is an imaginatively designed 1456 ft (443,80) long eleven-span precast, prestressed concrete arch structure. A key element in the design of this bridge is the use of curved U-shaped precast, post-tensioned arch segments that functioned as both load-carrying structural members and as self-supporting permanent forms. The deck is formed by standard AASHTO pretensioned concrete girders that frame into cast-in-place cross beams. The innovative use of precast arch segments and standard girders shortened the construction period and cost an estimated $2 million less than a similar cast-in-place concrete arch bridge. This article discusses the design challenge, design solution, aesthetics, structural design considerations, construction highlights, and cost breakdown.

Rehabilitation of the Fremont Street Bridge

The author presents the design-construction details that were employed in rehabilitating the Fremont Street Bridge, a 50-year-old old concrete arch structure situated near Pittsburgh, Pennsylvania. Precast decking and a two-piece precast floor beam assembly were among the construction techniques used to repair the bridge while maintaining uninterrupted traffic.

Engineering geology of the Gordon Dam, South West Tasmania

Summary The Gordon Dam is a double curvature concrete arch structure 140 m high, forming part of a hydro-electric scheme. The dam is sited on folded and faulted Precambrian quartzite. Driving adits was favoured over diamond drilling in siting the dam and for detailed investigations to prove the stability of the foundations. Considerable excavation on the left abutment was necessary to remove unfavourable rock and a continuous pre-split face of 122 m was produced. The geological conditions found during excavation were better than anticipated thus raising the computed factor of safety.

Survey Control for Concrete Dam Construction

The development of survey controls for Morrow Point Dam, a double-curvature, concrete-arch structure, 465 ft in height, was required through the phases of reconnaissance, site investigation, and preconstruction to satisfy the specific needs of the designer, and to fit the rough terrain. Statistics for the dam and power plant are given. Procedures and equipment used in establishing a modified second-order triangulation scheme and a first-order level net are explained. The method used in adjusting the triangulation scheme is presented. Planning survey controls to encompass specific structures was completed early in the construction phase. A description of survey procedures to bring accurate control into the blocks of the dam for each 7-1/2-ft placement-lift is given. Methods devised and equipment used in establishing vertical control in each keyway are described. A brief evaluation of planning field surveys to utilize modern electronic computing equipment is presented.

Measured Deformation Behavior of Glen Canyon Dam

Representative results obtained during 3 years of measurements from each of two systems installed to determine the deformation behavior of the Bureau of Reclamation's Glen Canyon Dam, a large concrete arch structure, are presented. The deformation is caused by water loading and by changing temperature of the mass concrete. Measurements are by precise triangulation from piers downstream from the dam to targets on its face, using a theodolite, and by observations on five plumb lines installed in formed vertical wells in the dam. Also, monuments in three wells which extend into the foundation near the toe of the dam are triangulated. The results show the deformation of the dam is comparable from the measurements by both systems which are independent of each other. The annual range of deformation from the plumb lines during a 60○ temperature range is approximately 1/2 in. at the top of the dam in its maximum section and the deformation of the dam is upstream approximately 1-1/2 in. for the period of record. The measurement system layout and photographs of apparatus are shown. The programs of periodic observations, field procedures, techniques, timesaving and error minimizing equipment devised by field personnel, computing methods, and results are described.