Papers by Keyword: Response Spectrum Method

Abstract: With the increasing population and unavailability of plain grounds in some regions, the need for high-rise buildings is increasing day by day. Buildings constructed on sloping terrain are more prone to earthquakes because of their uneven floor plans and elevations. This study examines the seismic behavior of high-rise buildings on both flat and sloping terrains, with a focus on comparing regular and irregular structural configurations. In this study a total of 25 G+15 RCC Step-back buildings with regular and irregular configurations such as Square shape, C-shape, U-shape, L-shape and Cross shape each of which are resting on grounds with sloping angles of 0º, 10º, 20º, 30º and 45º have been made using ETABS software as per IS 1893 (Part 1): 2016. The study employs the Response Spectrum Method to evaluate Storey Displacements, Storey Drifts, Base shears, and Time periods. It is observed that the storey displacement and storey drift decrease as we increase in sloping angle mainly due to curtailment of the columns, and the regular configurations of structures have better seismic performance than irregular configurations.

Abstract: The dynamic characteristics of Tukan Wujiang Bridge are analyzed numerically. The bridge, which is still under construction, is a continuous rigid frame bridge with high-piers and long-span in Wulong County, Chongqing, China. A spatial finite element model is established for the bridge with the finite element software ABAQUS. The natural vibration characteristics and effective modal participation mass of the bridge in the built-up case is obtained. The variation of dynamic characteristics of continuous rigid frame bridge subjected to the dynamic earthquake loading is studied, and the number of modes necessary to the vibration mode combination when applying the response spectrum method under the earthquake is obtained. In addition, the seismic response of the bridge is analyzed with both the response spectrum method and the time-history method, and the maximum response of structure under various probability of earthquake is obtained. The results of the two methods are compared. The comprehensive seismic performance of the bridge is analyzed and evaluated. The results show that the seismic performance of the rigid frame bridge satisfies the expected design performance.

Abstract: The response spectrum method was applied to calculate the seismic behavior analysis of a spillway weir gate. Based on the analysis of the structure performance, special attentions were paid to the stress state of the key parts on the surface and root of the pier. The results showed that the displacement and stress of the whole structure were related to the direction of earthquake excitation; large principal tensile stress and principal tensile stress area appeared in steep change points of geometry shape, special attention should be paid when calculating anti-seismic checking and reinforcement arrangement; the displacement and stress of the weir section met the standard requirements.

Abstract: With the continuous development of the marine oil industry, risers have become necessary equipment in offshore drilling engineering. On the basis of mode-superposition response spectrum method which is used commonly in anti-seismic design, the seismic responses of the marine drilling riser is analyzed on the theoretical and the related anti-seismic calculation formulas of the discrete system are promoted to the continuous system. The earthquake force and the resultant internal forces when the earthquake happening are analyzed and calculated. The calculation formulas of shear force and bending moment for each cross section of a riser under the earthquake action are deduced, which can offers some theoretical reference for riser engineering design when considering earthquake action.

Abstract: Basing on the reinforcement of a practical project, which is a reinforced concrete multi-span cantilever girder bridge, by changing section properties to improve the bearing capacity and seismic performance of the bridge. Then, a finite element model is established and solved by using the subspace iteration method, the frequency and vibration type is compared that of the bridge before and after reinforcement, the effectiveness of the new method on the structural dynamic characteristic is verified at the same time. Then, the seismic response of the bridge is calculated and analyzed by using the response spectrum method, which can provide method for reinforcement of similar bridge.

Abstract: In order to ensure the strength, stiffness and stability of the overall structure of three-ring roller coaster in the seism, the response spectrum method is used for anti-seismic analysis of the overall structure of three-ring roller coaster, the dynamic response under seism and anti-seismic characteristics is calculated, the safety of three-ring roller coaster under seism is verified, and practical method for anti-seismic analysis of roller coaster is explored.

Abstract: According to the actual engineering conditions of Haokou RCC Gravity Dam, the 3-D FEM model of the typical overflow dam section and its foundation is set up. Using the response spectrum method, the responses of earthquake acceleration, displacement and stress of the dam and their distribution laws were studied under the seismic loading, and the anti-sliding stability of dam is also analyzed. The calculation results show that under the design earthquake condition, the maximum principle stress response of dam body is 2.26MPa, which appears at the dam heel. The safety factor of stability against sliding on the face of the dam foundation is 1.43 and the stability against deep sliding is 3.2. So this dam section can meet the strength and stability requirements of standard, its earthquake-resistant safety could meet the requirements of standard.

Abstract: Take one long span double-curved arch bridge as the example, built the finite element model of bridge structure and analyzed the modeling method, dynamic features and response under ground motion. It demonstrates that response spectrum method could meet the calculation requirement in seismic analysis of the double-curved arch bridge, and the result accords with time-history analysis method. Bridge vibration type is dispersing in quality distribution of double-curved arch bridge; it should take adequate vibration types in bridge combination. At frequent earthquake, it is actual to considerate the coalition function between arch crown structure and the main arch ring. But at rare earthquake, the arch crown buildings of masonry structure is easy to be damaged, it is not suitable to considerate the coalition function in bridge reinforcement.

Abstract: Based on the characteristics of low tower and few cables in extradosed Cable-Stayed bridges, simulation models are established for investigations of structural dynamic characteristics under different design parameters, which is related to the practical engineering of Longjing Bridge. As the design radius and pier beam connection form are chosen for the variable, the paper is focus on the influence of dynamic characteristics under the two parameters in extradosed cable-stayed curved bridges. Since the earthquake response spectrum data from National seismic code in 2008 and with the CQC vibration mode combination method, the diversified models are built by Midas/civil so as to explore the earthquake response mechanism under different design parameters. The result show that these two design parameters have some great impacts on dynamic characteristics of extradosed cable-stayed curved bridges, which has direct effect on the bridge seismic performance. The conclusion is the important reference for practical engineering and providing basis for seismic design parameters, but also for seismic design and construction in extradosed cable-stayed curved bridges.

Abstract: Based on response spectrum method, the seismic behavior of a long span cable-stayed bridge is investigated through three dimensional finite element model established by ANSYS. By calculating the cumulative effective mass factors of the bridge, the minimum number of modes used for modal superposition analysis is obtained. Design acceleration response spectrums under two probabilities are used in the analysis. The response spectrums are input in the bridge longitudinal direction, vertical direction, transverse direction and combined horizontal and vertical directions. Displacements and internal forces results show that vertical component of the ground motion greatly influences the response of the bridge and there is significant difference between the results of the two probabilities.