Innovative prefabricated composite beams are continuously being introduced to enhance structural performance while minimizing costs and construction time. The prefabricated double-channel composite ...beam is a new section that offers improved structural performance, facilitates rapid assembly, and helps reduce construction time and costs. However, previous research on such beams has overlooked the importance of incorporating web openings for the installation of building services. Therefore, this paper aims to investigate the influence of web opening depth, length, and spacing on the behavior of prefabricated double-channel composite beams (DCCP). Static bending tests were carried out on a beam with circular web openings and three beams with varying elongated web opening lengths. Then, a finite element (FE) models of DCCPs with varying depth, length, spacing of web openings, sections and bolt pitch were performed to investigate their influence on the behavior of DCCP under sagging moment. The experimental and finite element (FE) results revealed that beams with elongated web openings experienced failure due to the Vierendeel mechanism, while the beam with circular web openings failed due to C-channel yielding and concrete crushing at midspan. The depth, length, and spacing of the web openings significantly influenced the ultimate capacity of the beams. As the size of the web openings increased, the ultimate capacity decreased, whereas an increase in the spacing of the openings led to a 3–5% increase in the ultimate capacity. A theoretical model was developed to calculate the ultimate capacity of DCCPs, and its predictions aligned with the experimental and FE results.
•Bending tests have been conducted on four composite beams with varying web opening lengths (DCCPs).•Numerically investigated the effect of varying web openings size, sections, and bolt pitch on the behavior of DCCPs.•A theoretical model was put forward for predicting the ultimate capacity of DCCPs.•The failure modes, yield patterns, bearing capacity, and ductility were investigated.•The investigation results demonstrated that the ultimate capacity decreases as the web openings size increases.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
2.
Megadim Railway Bridge, Israel Bloch, Jacob; Sokal, Jeshavahu; Mendelson, Eliezer
Structural engineering international : journal of the International Association for Bridge and Structural Engineering (IABSE),
19/8/1/, Volume:
7, Issue:
3
Journal Article
Peer reviewed
The Megadim Railway Bridge carries two railway lines over the Tel Aviv-Haifa Expressway. It has been sited near an existing single-track bridge. As there are plans to add two traffic lanes to the ...four-lane expressway, the existing bridge will have to be demolished, since it is too narrow.
The owner required that the new bridge be constructed without any disruption to train traffic and with only minimal disruption to road traffic. In order to meet these requirements, a structural system that used 400 t prefabricated beams was employed. The prefabricated beams, among the heaviest ever used in Israel, were cast at the site, hoisted into place and installed.
Full text
Available for:
BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
•Experimental study on post-fire cyclic performance of CFST column to steel beam joints with blind-bolted connections under a fully coupled time–temperature-load field.•A verified finite element ...analysis (FEA) model to investigate post-fire cyclic performance of blind-bolted CFST joints.•Numerical study on the effect of coupled fire exposure, long-term and cyclic loading.•Post-fire hysteretic model on blind-bolted CFST joints.
During the life-cycle of a building, the structure might be subjected to multiple hazards such as fire, earthquake and impact. Compared with the traditional structure design methods based on a single type of disaster load, the structure subjected to multiple and coupled disaster loads would be more dangerous and worth to be investigated. In this paper, the post-fire seismic behavior of concrete-filled steel tubular (CFST) column to steel beam joints with blind-bolted connections subjected to coupled fire and cyclic loads were investigated. A total of ten post-fire hysteresis joint tests were designed and conducted, and the testing parameters included heating time, post-fire column load ratio and thickness of fire protection layer. The test results indicated that the joint failure mode changed from column failure to connection failure when the post-fire column load ratio ranged from 0.3 to 0.6. Generally, the blind bolts in the panel zone of this joint specimen showed acceptable working performance in fire, but gap between the stee tube and beam end plate might be formed during the post-fire cyclic loading process. Finite element analysis (FEA) models were established to simulate and discuss the post-fire seismic performance of this type of blind-bolted CFST joints under the coupled fire and loading process. Finally, a simplified post-fire hysteretic relationship model for this type of joint was proposed.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The seismic behavior of the traditional top and seat angle beam-column connection was experimentally evaluated using a half-scaled prefabricated exterior beam-column connection subassembly. Then, an ...ensemble of three post-tensioned beam-column connections using reduced length basalt fiber reinforced polymer (BFRP) tendons was tested with three different tendons' post-tension (PT) force levels of 15.9, 30, and 50% of the tendons' ultimate strength. Following that, another group of three additional subassemblies containing both reduced length BFRP tendons, as post-tensioning devices, and top and seat angles, as energy dissipation (ED) devices, was tested with the same three post-tension force levels used in the previously tested group. Finally, an analytical model was proposed to capture the moment-relative rotation response of the traditional top and seat angle and the connection combining both the top and seat angles and the BFRP tendons. The results showed that connections containing BFRP tendons only, with the lowest PT force level, provided the same envelope of the top and seat angle connection, and further enhancement could be achieved by increasing the PT force level. Also, the addition of the BFRP tendons to top and seat angle connection improved the connection strength, initial stiffness, post-yield stiffness, and reduced the residual drift. In addition, the proposed analytical model predicted the moment-relative response well, which ensures the reliability of the model in designing such connections.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper proposes a prefabricated beam–column joint with L-shaped stiffeners based on the traditional semi-rigid joint and end-plate connection. The joint is suitable for multi-story prefabricated ...steel frames and a fully bolted assembly construction. To study the seismic performance and failure modes of the joints, cyclic loading test were conducted on three full-scale specimens of prefabricated beam–column joints with L-shaped stiffeners. Furthermore, the rotation stiffness and bearing mechanism of the joint were obtained by an improved component method proposed in this paper. The results of the tests indicated that the failure modes of the joints were buckling and tearing of the flange and web of the beams. Additionally, the load-carrying capacity as well as ductility and energy dissipation capacities of the joints under cyclic loading can be improved by increasing the length and thickness of the L-shaped stiffeners. The rotation stiffness of the joint satisfies the Eurocode 3 moment–rotation model requirements and is suitable to improving the seismic performance analyses of prefabricated steel structures.
•The mechanical properties of prefabricated beam–column joints with L-shaped stiffeners were investigated in this paper.•The Moment–rotation curves of joints were established, and the specimen has a strong plastic deformation capacity.•The bearing mechanism is calculated, and the theoretical values agree well with the test values.•The rotation stiffness of joint is established by component method and the initial stiffness is divided into four parts.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper presents a novel form of prefabricated H-shaped steel beam to concrete-filled steel tubular (CFST) column joints. The behavior of such novel beam-to-column joints was investigated through ...cyclic loading tests on four joint specimens. The examined parameters included the thickness and the yield stress of the column steel tube, and the distance between the transfer sleeve and the flange of the steel beam. The hysteretic behavior, failure modes, flexural stiffness and capacity, and energy consumption of the joint specimens were discussed in detail. Particularly, the effectiveness of the proposed column-to-column connections, which are critical sections of the proposed joints, in transferring bending moments between column segments was evaluated. The test results indicated that the proposed beam-to-column joints exhibited great flexural capacity and energy dissipation capacity. It was also found that the thickness and yield stress of the steel column tube significantly affect the flexural capacity of the column-column connection and the shear deformation of the panel zone. Finally, accurate finite element model was developed for the prediction of main mechanical properties, such as initial stiffness, yield strength, and maximum strength.
•A H-shaped steel beam to prefabricated concrete-filled steel tube column joint with column-column connection was investigated.•The flexural bearing capacity of column-column connections was discussed.•Thicker tubes and high-strength steels improved the flexural capacity of connections.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As one of the most sophisticated structural types in rapid industrialized bridge construction technology, the fabricated beam bridge has been widely used in road network system for a long time. The ...prominent disease of this type of structure is the degradation of the lateral cooperative capability, that is, the deterioration of the hinge joint stiffness. This paper proposes a monitoring and evaluation method for the lateral connection stiffness based on the multiple-beams theory, which has the concise physical meanings and can be easily implemented. On this basis, a new damage identification method and index extracted from the mode shape information of the system is proposed in this paper. To verify the effectiveness of the proposed indicator ARCR, Shanghai Tongji Road viaduct is taken as the engineering background. Results shows that the theoretical analysis results are consistent with physical truth, the proposed indicator can reasonably reflect the degradation degree of the joint and locate the damaged joint.
Full text
Available for:
NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
•The complex ultrasonic field in the corrugated clad plate is analyzed and an effective filtering scheme is proposed.•The relationship between LU-SAFT imaging efficiency and imaging quality is ...discussed.•A calculation model of interface profile based on ellipse common tangent line is proposed.•The imaging of multi metal laminate with complex interface is realized.
Eccentrically braced steel frames have great ductility and energy dissipation, but their elastic stiffness is influenced by the length of the braces. The stiffness of these frames is important for computing story drifts and link rotations, which have prescribed limits. The yield and ultimate bearing capacity of eccentrically braced steel frames can be predicted by analyzing their individual components. This paper proposes a method to calculate the elastic stiffness and bearing capacity of K-type, D-type, and V-type eccentrically braced steel frames. To calculate the elastic stiffness of these frames, the displacement of a story can be obtained by summing the deformations of the individual components. The link shear and brace axial force of a story are also considered using structural mechanics. This allows for estimating the elastic stiffness of eccentrically braced steel frames in the early design phase. Based on the virtual work principle and the ideal failure mode of these frames, the yield and ultimate bearing capacity of eccentrically braced steel frames are proposed using frame drift angle and verified by experimental results. The theoretical stiffness of these frames is compared with finite element models. The finite element analysis and experimental results show that the elastic stiffness, yield bearing, and ultimate bearing are very close with only about 10% error, verifying the high accuracy of the formula suggested in this paper.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Earthquake-resilient structures have been widely recognized and applied in the seismic field of prefabricated steel structures due to their excellent performance. The prefabricated sinusoidal ...corrugated web steel beam-column joint (PSCWJ) with the earthquake-resilient design concept has been previously proposed. To study the impact caused by the bolt parameters on the seismic behavior of the new PSCWJ, five specimens were designed, with varying the number of flange connecting bolts, type of bolt holes, and interval between the middle bolts. A low cycle reciprocating load test and the finite element (FE) simulations were conducted on the specimens to determine the failure mode, energy dissipation capacity, ductility, hysteretic curves, sliding curves, strain curves, skeleton curves, and other main indexes on seismic performance. And the study indicates that the PSCWJ has excellent bearing capacity and seismic performance, the new prefabricated joint can realize the dual energy dissipation by buckling and sliding of the flange cover plate (FCP), and the number of flange connecting bolts directly determines the sliding load of FCPs. A rational interval between middle bolts can control the buckling load of FCPs and provide the joint with a satisfactory bearing capacity. The setting of slotted hole can increase the rotation and energy dissipation capacity of the joint. Further, the energy dissipation performance of the repaired specimens is stable under the low frequency constant amplitude loading, thereby ensuring that the PSCWJ can be used as a damper.
Display omitted
•Five PSCWJ specimens are subjected to cyclic loading tests and repair tests.•The effects of bolt design parameters on joint seismic performance are studied.•The failure mode and energy dissipation capacity of PSCWJ are investigated.•Finite element numerical simulations are carried out on the test specimen.•The repair program of replacing the connection device is feasible.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to ensure reliable seismic performance, controllable plasticity and recoverable post-earthquake function of precast concrete (PC) frame beam-column joints, this study introduces an ...innovative artificial controllable plastic hinge (ACPH) incorporating friction side plates (FSPs) and energy-absorption boxes (EABs) for connection and energy dissipation. Five specimens were fabricated to evaluate the performance of the ACPH. Initially, design criteria were established, and the sliding bending moment (Mslide) of the FSPs was assessed under various surface treatments and bolt preloads. The proposed theoretical formula was validated through two low cycle reciprocating tests. Subsequently, quasi-static experiments were conducted on three specimens with different forms of EABs, examining hysteresis performance, strength, and stiffness degradation. The research findings reveal a clear two-stage yield mechanism in the specimens. The first stage involves rotational friction of the FSPs, while the second stage is characterized by the failure of the EABs. Plastic damage is predominantly localized in the EABs, and the incorporation of stiffeners between the dog bone-energy absorption plates (DB-EAPs) can improve their load-bearing capacity and stiffness.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
