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1

Research on reinforcement technology of existing double-way curved arch bridge

Zhang Kexin, Qi Tianyu, Xue Xingwei, Li Yanfeng, Zhu Zhimin

Archives of Civil Engineering

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2021

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Vol. 67, nr 2

581--595

EN

Two-way curved arch bridges inherit the fine tradition of masonry structures, making full use of the advantages of prefabricated assembly, it adapts to the situation of no support construction and no large lifting machine and tools, and has the characteristics of convenient construction method and saving material consumption. In appearance, the two-way curved arch bridge has strong national cultural characteristics. The prefabricated components of the two-way curved arch bridge are fragmentary, complicated in bearing and poor in integrity. Most of the two-way curved arch bridges in service have been built for a long time and lack of maintenance and management. Increasing the cross-section reinforcement method is one of the two-way curved arch reinforcement methods. It has a significant effect, convenient construction, good rigidity and stability characteristics after the reinforcement. Through theoretical analysis, combined with a static load test results of the assessment of the bridge reinforcement effect. Through load test, it is found that the deflection of the arch rib after reinforcement is reduced by 9%~19% and the strain of the arch rib is reduced by 12%~22%. Through finite element calculation, the crack width of the reinforced arch rib decreases by 8.3%~14.2%. The results show that the stress and deflection are greatly improved by the method of increasing section.

2

Seismic performance of circular reinforced concrete columns subjected to compression, bending and torsion with low and moderate shear span ratio

Jiao Chiyu, Liu Yang, Wei Biao, Li Jianzhon, Hu Zhangliang, Zhu Gexi

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

836--851

EN

Under the action of an earthquake, the piers of urban curved bridges are usually subjected to compression, bending and torsion due to the geometric irregularity and with low and moderate shear-span ratio. To explore the seismic performance of piers under combined actions, this paper made a theoretical analysis on the seismic performance of four circular RC columns under combined action with low and moderate shear-span ratio through experimental research. Taking the shear-span ratio and torsion-bending ratio as the main variables, cyclic bending loading and combined cyclic bending and torsion loading were carried out on the columns, respectively. The results showed that the increase of torsional effect and shear effect will increase the failure height of the piers and weaken the energy dissipation capacity and bearing capacity. Through the extraction of characteristic points in the test data, the relationship between force, displacement and torsion-bending ratio of columns with shear-span ratio below 4 was fitted. The bending and shear restoring force models of columns with spiral stirrups and small torsion-bending ratio were established. Moreover, based on the variable angle truss theory, the concrete improvement coefficient β was introduced, and the formula of torsional bearing capacity of columns under combined actions with low and moderate shear-span ratio was deduced. Compared with the test data, when the value of β was taken as 1.1, the proposed formula could be well applied to the calculation of bearing capacity of piers with torsion-bending ratio below 0.2 under combined actions with low and moderate shear-span ratio.

3

Mosty o konstrukcji cięgnowej zaprojektowane przez biuro projektów w Brnie

Stráský J.

Inżynieria i Budownictwo

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2012

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R. 68, nr 2

91-99

PL

Przedstawiono liczne przykłady konstrukcji cięgnowych (podwieszonych, extradosed i wiszących) zaprojektowanych w firmie konsultingowej Strasky, Husty and Partners Ltd. w Czechach i jej biurach zagranicznych. Przykłady te stanowią ilustrację rozwoju tych konstrukcji w okresie ostatnich ponad dwudziestu lat.

EN

Cable-stayed, extradosed and suspension bridges built according to SHP design in the Czech Republic, Spain and USA are described in terms of their architectural and structural solution and technology of the construction. Their architectural and structural arrangement was of these bridges was developed from their basic function- to bridge a natural obstacle or another man-made thoroughfare. Concrete and steel structures suspended in bridge axis or on their outer edges are discussed. Experimental testing of curved cable supported bridges is also presented.

4

A study on thermal behaviour of curved steel box girder bridges considering solar radiation

Kim S. H., Cho K. I., Won J. H.

Archives of Civil and Mechanical Engineering

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2009

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Vol. 9, no 3

59-76

EN

Solar radiation induces non-uniform temperature distribution in the bridge structure depending on the shape of the structure and shadows cast on it. Especially in the case of curved steel box girder bridges, nonuniform temperature distribution caused by solar radiation may lead to unusual load effects enough to damage the support or even topple the whole curved bridge structure if not designed properly. At present, it is very difficult to design bridges in relation to solar radiation because it is not known exactly how varying temperature distribution affects bridges; at least not specific enough for adoption in design. Standard regulations related to this matter are likewise not complete. In this study, the thermal behavior of curved steel box girder bridges is analyzed while taking the solar radiation effect into consideration. For the analysis, a method of predicting the 3-dimensional temperature distribution of curved bridges is used. It uses a theoretical solar radiation energy equation together with a commercial FEM program. The behavior of the curved steel box girder bridges is examined using the developed method, while taking into consideration the diverse range of bridge azimuth angles and radii. This study also provides reference data for the thermal design of curved steel box girder bridges under solar radiation, which can be used to develop design guidelines.

PL

Promieniowanie słoneczne powoduje niejednorodny rozkład temperatury w konstrukcji mostu i zależny od jego kształtu oraz padających cieni. Szczególnie w przypadku mostów zakrzywionych ze stalowych dźwigarów skrzynkowych niejednorodny rozkład temperatur wywołany promieniowaniem słonecznym może prowadzić do powstania wyjątkowych sił wystarczających do zniszczenia podpór lub nawet zniszczenia mostu, o ile jego konstrukcja nośna nie została odpowiednio zaprojektowana. Obecnie projektowanie mostów z uwzględnieniem promieniowania słonecznego jest bardzo trudne, ponieważ wpływ zmiennego rozkładu temperatury na konstrukcję mostu nie jest dokładnie znany, jak również nie jest określony sposób uwzględnienia tych wpływów w projektowaniu. Nie istnieją również żadne normy dotyczące tego zagadnienia. W pracy przedstawiono analizę zachowania mostu uwzględniającą działanie promieniowania słonecznego. Do analizy użyto metodę przewidywania trójwymiarowego rozkłady temperatury w mostach zakrzywionych w planie. W metodzie tej wykorzystane zostało teoretyczne równanie promieniowania słonecznego oraz program do analizy metodą elementów skończonych. Przeprowadzono badania zachowania mostu przy uwzględnieniu różnych zakresów kąta azymutu oraz promieni zakrzywienia mostu. Praca stanowi źródło - możliwych do wykorzystania w projektowaniu - informacji dotyczących zagadnień termicznych w mostach zakrzywionych o przęsłach ze stalowych dźwigarów skrzynkowych pod wpływem promieniowania słonecznego.

5

Dynamic behaviour of bridge decks curved in plan

Sasmal S., Ramanjaneyulu K.

International Journal of Applied Mechanics and Engineering

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2007

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Vol. 12, no 4

1117-1134

EN

In this paper, a detailed study has initially been carried out, using SAP2000, to evaluate the adequacy of a griIIage model in refleeting the vibration characteristics of a curved bridge in comparison with the finite element model since the griIIage model is widely used by professional engineers due to its simplicity in modeIIing and interpretation. From this study, it has been noted that the grillage model is not capable of retleeting the dynamic characteristics accurately. In view of this, a finite element formulation and a computer program have been developed using eight noded isoparametric curved quadratic shell finite elements to assess the influence of different parameters, viz., curvature, aspect ratio, on the dynamic response of bridges curved in plan. However, the question of whether or not the deck slab curved in plan should be assumed to be rigid in its pIane during vibration, is yet to be answered. Therefore, the effect of curvature on in-plan deck tlexibility during in-pIane vibration of bridge decks curved in plan is also studied. The parametric study carried out in this investigation to establish the relationship between the structural behaviour of curved bridge deck with that of straight bridge would prove to be very useful for bridge engineers to readily assess the behaviour of bridge decks curved in plan, based on the responses for a straight bridge deck.