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Wooden covered bridges attract attention due to their architectural appearance and manufacturing technique. In this study, an ancient wooden covered bridge in Taoyuan, China, has been investigated, mainly with respect to its construction form and mechanical behavior. First, the same type of raw material used for the bridge, namely, beech, was tested to obtain its mechanical properties. Then, the material experimental values were used in a finite element model to study the mechanical behavior of the bridge, and the stress state and internal forces of the bridge were obtained. The numerical results indicate that the maximum deflection of the bridge of 10.73 mm under gravity load meets the requirements of not exceeding L/600 in the specification while it reaches 15.62 mm under both the gravity load and crowd load, exceeding the limit by 1.3%. The maximum and minimum normal stress of 1.13 MPa and -2.03 are much less than the ultimate tensile and compression strength of the wood, respectively. This means that the structural safety performance of the ancient wooden covered bridge is acceptable if the pedestrian number be controlled effectively. Finally, some tiny damage of the bridge was apparent. Some suggestions were provided according to the numerical results and the complex actions of long-term loads and a severe environment on the bridge to preserve this old historical bridge.

Wooden cantilever covered bridges are known for their marvelous shapes and manufacturing technique. Many wooden cantilever covered bridges were constructed during Ming and Qing Dynasties in Anhua province, China, due to the “Tea-Horse Trade” policy. The excellent performance of wooden materials and exquisite building techniques have kept these wooden bridges well-preserved and worthy of investigation. This paper conducted a comprehensive review of wooden cantilever covered bridges in Anhua, especially for the eight bridges listed as historical and cultural heritage protected at the provincial or the national level. The discussions covered the historical background of the bridges, their locations and dimensions, and the details of their structures including the cantilever systems, corridors, and roofs. Moreover, the cultural background was introduced to better understand the meaning of the decorations carved on the bridges and the logic of location selections.

Ancient Chinese covered bridges are attracting increased attention due to their architectural appearance and manufacturing technique. In this study, an ancient single-arch covered bridge, Yinjia bridge, in Peach Blossom Spring in China has been investigated, mainly in the field of its cultural background, art aesthetics, and mechanical behavior. The methods of field measurement and finite element analysis were combined. First, the structural dimensions and construction of Yinjia bridge are introduced. Then, the historical origin and cultural connotation, the bridge corridor and decoration are considered, and the Chinese culture reflected behind the bridge design are investigated. A finite element model was built to study the mechanical behavior of the bridge. The numerical results indicate that the maximum vertical deflection of 4.32 mm is under but close to the limit of L/600, while no horizontal deflection exists at the foot of the arch crown. The maximum and minimum normal stress of 0.04 MPa and -0.12 MPa in components of bridge corridor are much less than the ultimate values of wood. The maximum compressive stress of 0.05 MPa of the bridge arch is within the limit value of the ultimate compressive strength of stone. This means that the structural safety performance of this ancient bridge is acceptable, and indicates that no significant structural damage has been found yet in the Yuxian bridge.

This study examines the structural characteristics and technical principles of the hybrid framing cantilever bridges along the Longchuan River in Tengchong, Yunnan, China, taking the Yezhuqing Bridge as a case example. Such bridges integrate diverse construction techniques—including inclined cantilevers, iron chains, three-sided arches, and strut frames—showcasing the craftsmanship characteristic of a region shaped by cultural blending. This paper first analyzes the structural design and mechanical principles based on the bridge's form, and then examines construction details to understand material selection, reconstruct fabrication methods, and explore craftsmanship thinking. The findings reveal that in the structural design, iron chains, strut frames, and three-sided arches each take on distinct load-bearing roles in a cantilever bridge, enabling it to achieve a large span. By coordinating structural components, this bridge type does not require scaffolding during construction, instead relying on the components themselves for mutual support throughout the building process. In terms of construction details, skillful arrangement of elements like wooden pegs enhances convenience and precision during construction, while ensuring overall integrity and stability. Additionally, this study examines existing structural vulnerabilities and past restoration issues, providing insights for future conservation efforts.

Wooden cantilever covered bridges are known for their marvelous shapes and manufacturing technique. Many wooden cantilever covered bridges were constructed during Ming and Qing Dynasties in Anhua province, China, due to the “Tea-Horse Trade” policy. The excellent performance of wooden materials and exquisite building techniques have kept these wooden bridges well-preserved and worthy of investigation. This paper conducted a comprehensive review of wooden cantilever covered bridges in Anhua, especially for the eight bridges listed as historical and cultural heritage protected at the provincial or the national level. The discussions covered the historical background of the bridges, their locations and dimensions, and the details of their structures including the cantilever systems, corridors, and roofs. Moreover, the cultural background was introduced to better understand the meaning of the decorations carved on the bridges and the logic of location selections.

In this paper, given the shortcomings of jellyfish search algorithm with low search ability in the early stage and easy to fall into local optimal solution, this paper introduces adaptive weight function and elite strategy, improving the global search scope in the early stage and the ability to refine the local development in the later stage. In the numerical study, the benchmark problem of dimensional optimization with a 10-bar truss structure and simultaneous dimensional shape optimization with a 15-bar truss structure is adopted, and the corresponding penalty method is used for constraint treatment. The test results show that the improved jellyfish search algorithm can provide better truss sections as well as weights. Because when the steel main truss of the large-span covered bridge is lifted, the site is limited and the large lifting equipment cannot enter the site, and the original structure does not meet the problem of stress concentration and large deformation of the bolt group, so the spreader is used to lift, and the improved jellyfish search algorithm is introduced into the design optimization of the spreader. The results show that the improved jellyfish algorithm can efficiently and accurately find out the optimal shape and weight of the spreader, and through Midas Civil simulation, the spreader used can meet the requirements of weight and safety.

America’s first documented wooden covered bridge was erected at Philadelphia, Pennsylvania in 1805. Hundreds were constructed within two decades and at least 10,000 by the later 1800s. As settlers moved West, broad rivers were crossed with inventive structures incorporating timber trusses ingeniously developed by carpenters. Called covered bridges because of the roof and siding needed to protect the timber trusses, they became ubiquitous features on the American landscape. Over the past two centuries, most covered bridges were lost to flood, ice, arson, lightening, decay, as well as “progress,” replaced by “modern” iron, concrete, and steel spans. Of some 700 covered bridges remaining, many are mere replicas of their original forms no longer supported by timber trusses. Genuine historic bridges remain largely from the last half of the 1800s while civic boosterism has led to claims of earlier dates with often questionable authenticity. This essay presents three wooden covered bridges constructed in the 1820s along a 10-mile stretch of the Wallkill River in New Paltz, New York. Of the three, only Perrine’s Bridge, constructed first in 1821 and covered in 1822, is still standing with intact Burr timber trusses. Perrine’s is an iconic structure with exceptional heritage value because of authentic re-building and restoration in 1834, 1846, 1917, and 1968. Using documentary records, this essay establishes an accurate intertwined chronology for the three bridges, detailing nineteenth century building practices and contentious mid-twentieth century struggles pitting preservationists wanting authentic restoration against those wanting removal.

This study aims to establish finite element models to investigate the seismic performance of typical wall piers used in beam-type covered bridges. The impacts of the mesh sensitivity and load pattern of the selected multi-layer shell element model on the out-of-plane seismic performance are evaluated, and comparisons with the seismic behaviors captured by a force-based beam–column element model are conducted. An analysis is carried out to determine the displacement ductility ratios in each damage state. The applicability of the limit values of the out-of-plane damage states reported in previous studies is assessed and validated. The results showed that in practice, no great improvement can be achieved through the addition of additional elements, from the comprehensive perspective of the global force‒displacement curves. Nevertheless, the pattern of loading is vital to the seismic performance of a wall pier, and a wall pier installed with three bearings is assumed to be more favorable for a covered bridge subjected to earthquake forces. The multi-layer shell element model is more applicable than the force-based beam–column element model for characterizing the seismic performance at the local positions of the wall piers under different lateral loading patterns. There is a limited divergence in the displacement ductility ratios of at the local position of a wall pier under the application of two different lateral loads in the same damage state. This finding verifies the feasibility of using the limit values of conventional column piers for out-of-plane wall piers in various damage states. The critical values for damage state division for the wall pier of interest can be taken to be 0.27, 1.00, 2.33 and 5.33.

To investigate the seismic behavior of the wall pier of a covered bridge, the multi-layer shell element in OpenSEES was used to carry out the numerical analysis under a horizontal low cyclic loading in the weak axis direction. The effects of the mesh divisions of the wall pier models were evaluated and the hysteretic curves, skeleton curves, bearing and energy dissipation capacity, stiffness degradation and displacement ductility of the wall pier with different lateral loading modes were mainly researched. The results demonstrate that the discretization of layers along the thickness direction of the multi-layer shell element model has a very limited effect on the hysteretic and skeleton curves. The mesh division of the horizontal direction depends on that of the vertical, and the vertical mesh spacing shall be longer than the plastic hinge with a length of 0.5744 m. The arrangement of the loading points is critical for the seismic behavior of the wall pier. The pier suffering the force from the five points presents a relatively strong energy dissipation and larger ductility, but this layout may cause a more concentrated force at the local position. When the loading points are evenly distributed, the capacity and displacement changes sharply and the ductility diminishes. Successively, the seismic performance indexes at the local position of the wall pier tend to be more consistent with the increasing loading points. The deformation and energy dissipation capacity of the nearby position with the denser side loading points becomes larger, but this has a minor impact on the seismic performance of the position far from the points. The wall pier without the bent cap and with three bearings set is supposed to be more reasonable for the covered bridge through the overall analysis of seismic performance.

Description of historical covered bridge over Hnilec river so called bottom bridge in Gelnica near the station. History of the bridge. Way of construction of the bridge. Its structural system. Photographs of the bridge and its details. Scheme of the bridge.