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The paper deals with the verification of the stability of a new design concept of a hybrid harvester intended for thinning and with the determination of deviation between two methods of measuring the machine’s center of gravity, i.e., between the methods of determining the center of gravity using the SolidWorks software made by Dassault Systems and using portable vehicle scales with the function of gravity center calculation. The machine was measured in five different positions from going up or down the slope or driving along the contour line. The new prototype of a harvester with a non-conventional rigid frame and both axles steered was found to be unstable at the maximum reach of hydraulic boom if it is situated at a right angle (±90°) to the machine longitudinal axis. A comparison of the two methods of determining the center of gravity resulted in a total deviation of 8.41%, with the deviation for x being on average 14.36% and for y only 3.08%.

In order to fully understand contact dynamics on a trampoline, a simulation approach using a musculoskeletal model coupled with a dynamic model of the trampoline is essential. The purpose of the study was to examine dynamics and selected lower extremity muscle forces in a landing and jumping movement on a trampoline, using a combination of finite element modeling and musculoskeletal modeling. The rigid frame of the trampoline was modeled in ADAMS and coupled with a finite element model of the elastic trampoline net surface in ANSYS. A musculoskeletal model of an elite trampoline athlete was further developed in LifeMod and combined with the finite element model of the trampoline. The results showed that the peak trampoline reaction forces (TRF) were 3400 N (6.6 BW) and 2900 N (5.6 BW) for the left and right limb, respectively. The right hip, knee and ankle joint reaction forces reached the maximum between 3000-4000 N (5.8 – 7.7 BW). The gluteus maximum and quadriceps reached the maximum muscle force of 380 N (0.7 BW) and 780 N (1.5 BW), respectively. Asymmetric loading patterns between left and right TRFs and lower extremities joint reaction forces were observed due to the need to generate the rotational movement during the takeoff. The observed rigid and erect body posture suggested that the hip and knee extensors played important roles in minimizing energy absorption and maximizing energy generation during the trampoline takeoff.

The out‐of‐plane displacement (OPD) of a circular dielectric elastomer actuator (DEA) membrane has been explored in recent years for a variety of important applications. Circular DEAs consist of an elastomer membrane that is prestretched to a rigid frame and coated with compliant electrodes. Such a simple configuration has found many interesting applications such as in pumps, pulse tracking, hopping search and rescue robots, dielectric elastomer generators for renewable energy harvesting, linear actuators, and many others. Here, we present an easy‐to‐implement solution framework of the OPD for circular DEAs via a detailed numerical solution using the shooting method (SM) on a system of differential algebraic equations (DAE). The material model incorporated follows the robust Gent hyperelastic representation, and a comparison (of the OPD of a single‐cone DEA) against a neo‐Hookean based solution is included. The SM‐based numerical solution to the resulting boundary value DAE problem is applied to a practical range of values based on the reported literature. Analysis of the results and comparison against other studies are provided. The current work provides a go‐to framework for implementation in further research and development that can be useful to a broader audience including nonexperts in the field of soft robotics.

This research reviews a historical graphical method for the analysis of rigid frames. As the basis of this method, the graphical analysis methods for statically indeterminate beams, as well as determinate ones, were also reviewed. This method for rigid frames was presented by William Wolfe in 1921 [1]. Although somewhat rudimentary and almost forgotten, it possesses a special cognitive value comparing to the analytical and numerical methods. The current mainstream of the study on graphic statics pays limited attention on the application of graphic statics to rigid frames, as well as to hyperstatic beams. However, exploration on the analysis methods of these structure types was an important part of the history of graphic statics. Such explorations have occupied a large portion of some of the classic works of graphic statics. After the introduction, this paper reviews the origin and basis of the graphical method for rigid frames, revealing the history and system of the technique behind the graphical method for rigid frames. The methods for beams will be explained in more technical details in the following section, enabling readers to readily comprehend the explanation of the method for rigid frames in the next part. After the technical account, the advantages and disadvantages of this method for rigid frames are discussed. The author argues that this graphical method for rigid frames, notwithstanding its present limitation, is potential to be developed into a design method for architects to explore the form of rigid frames perceptively.

This research seeks a perceptive design approach for hyperstatic rigid frames which can provide more insights into the relations between form and inner forces. This approach is based on the historical graphical analysis methods for the hyperstatic rigid frames. This method is further developed and parameterized to overcome its shortcomings and better serve as an intuitive, interactive, and chronology-free design approach. Hyperstatic rigid frames are one of the most used structural types in the building industry. Bending moment is often the major dominant factor that governs the design of sections of structural members. Simultaneously, the sections of members also affect bending moment distribution by determining bending stiffness and the balance of forces. The current design practices of frame members are often material-inefficient because they usually respond to a localized peak of loading with constant section dimensions. Although the frames with constant sections may be more economical to fabricate and construct, their material inefficiency can lead to an excess carbon footprint. Besides, the aesthetic value of varying sections is often unexploited. Frames are unthinkingly designed as faceless supports by default instead of an element of architectural expression. To settle the terms and parameters of such structural problems requires the coordination of form (global geometry + varying section dimensions which dictates bending stiffness) and bending moment, and a higher level of involvement of architects in section dimensioning. Current numerical methods provide not enough insights into the relationship between the moment of inertia and resulting bending moment. The resulting approaches are not so intuitive and interactive; this results in a guess-and-check process with a poor understanding of the reciprocal influences of involved parameters. Moreover, they often deter architects with their demand for a structural experience hard to acquire. Graphical method, in particular Graphic Statics, is the potential to express structural relations more intuitively and provide insights into the structural problems, as geometry can describe forms, forces, AND magnitudes more intuitionally, Hence, it could facilitate the smart design and it is more comprehensible to architects. This research starts with an in-depth historical review of the analysis methods for rigid hyperstatic frames using Graphic Statics. This review reveals that statically indeterminate rigid portal frames under vertical loading can indeed be solved – and was solved – with Graphic Statics [figure 1]. This method is potent in analyzing frames with varying sections, and thus could be However, the historical method of hyperstatic rigid frames was limited to orthogonal portal frames under vertical loading. The result can also be rather cumbersome due to the limit of hand-drawing. The error can be significant for frames with static indeterminacy of more than one degree, partly Moreover, this is an one-way chronology approach which is not efficient for design. Figure 1. historical methods of analyzing a portal frame with graphic statics (W. Wolfe 1921) To overcome these limits, this research presents a solution for portal frames under horizontal loading using Graphic Statics. The portal frames with oblique members are also explored. In addition, a technique is proposed to address the static indeterminacy more precisely. Furthermore, this research parameterizes such a graphical environment to enable an analysis and design approach that is more intuitive, interactive, and chronology-free: The method is intuitive because all the relations are expressed explicitly on diagrams. Interactive because form and bending moment are simultaneously and dynamically steered by designers. Chronology-free because the deductive process undertaken by the designer can be switched whenever desired. This integrated method can facilitate designers to balance space and structural needs and render structural forms both innovative and structurally efficient.

In the present work, a new dynamical model with a single rigid frame driven by two pairs of vibrators, of which each pair of vibrators is engaged with each other by gear mechanism, is proposed to explore the composite synchronization of the system. The motion differential equations and vibration responses of the system are given first. The theory condition for achieving composite synchronization of the system is obtained, by using the average method to deduce the average torque balance equations of the two pairs of vibrators. According to the Hamilton’s theory, the system stability condition is presented, and it is mainly determined by the structural parameters of the system. The synchronous stable regions and stability ability versus the key parameters of the system are qualitatively discussed in numeric, and further quantitatively verified by simulations. It is shown that, in engineering, the reasonable working points of the system, should be selected in the region where the stable phase difference of the two pairs of vibrators is stabilized in the vicinity of zero. Only in this way, can the exciting forces of the two pairs of vibrators be positively superposed, and the linear motion of the system in the vertical direction be realized.

The current paper investigates the dynamical property of a pendulum attached to a rotating rigid frame with a constant angular velocity about the vertical axis passing to the pivot point of the pendulum. He’s homotopy perturbation method is used to obtain the analytic solution of the governing nonlinear differential equation of motion. The fourth-order Runge-Kutta method (RKM) and He’s frequency formulation are used to verify the high accuracy of the obtained solution. The stability condition of the motion is examined and discussed. Some plots of the time histories of the gained solutions are portrayed graphically to reveal the impact of the distinct parameters on the dynamical motion.

Thermal effect is an essential factor in the durability and safety of concrete bridges. Therefore, this paper mainly studied the concrete bridge box girder temperature distribution and thermal effect under solar radiation and the thermal load. With a concrete rigid frame bridge as the engineering background, the temperature distribution of the box girder on a clear summer day was observed. Then, according to the solar physics and heat transfer theory, the different surfaces of the box girder cross-section are classified based on the heat transfer conditions, and the variation of solar radiation on different surfaces is investigated. The temperature field of the box girder is simulated by ANSYS. To obtain the extreme thermal condition, the meteorological data of the bridge site from 1990 to 2020 are collected. The data are fitted by generalized extreme value distribution to obtain the extreme temperature and average wind factors in the bridge design lifetime. Combined with the solar radiation, temperature, and wind factors, the extreme thermal condition of the concrete box girder is obtained. Lastly, the thermal effect of the box girder under the extreme condition is analyzed, and the thermal stress is compared with the allowable stress in the design code. The results show that the girder temperature difference is closely related to the solar radiation intensity and heat transfer conditions, and the solar radiation intensity is the more critical factor. The tensile stress caused by the extreme thermal load is more significant than the design strength value in the girder cross-section. The results also provide a method to obtain the extreme thermal condition and evaluate the impact of the thermal effect on concrete box girder bridges.

Concrete bridges are used for both highways and railways roads. They are characterized by their durability, rigidity, economy and beauty. Concrete bridges have many types such as simply supported girder bridges, arch bridges and rigid frame bridges. However, for very large spans, arch bridges are more economic in addition to their beauty appearance. In this research, a geometrical structural optimization study for a deck concrete arch bridges using Genetic Algorithms technique is presented. This research aims mainly to demonstrate a methodology to find the least cost design, in term of material volume, by finding the optimal profile. A Finite Element numerical model is used to represent the arch structure. The MATLAB programing platform is used to develop codes for Genetic Algorithms optimization technique and Finite Element analysis method. The resulted design from the optimization process is compared to traditional design and an obvious cost reduction is obtained. Keywords: Optimization, Genetic Algorithms, Finite Element, Arch bridges

Asynchronous vibration was generated between the main bridge and approach spans or abutments due to differences in stiffness and mass during an earthquake, thus further leading to pounding at the bilateral beam ends. By taking a T-shaped rigid frame bridge as an example, the bilateral pounding model was abstracted, and the earthquake response spectra considering pounding at the bilateral beam ends were studied, including the maximum displacement spectrum, the acceleration dynamic coefficient spectrum, the pounding force response spectrum, and the response spectrum for the number of pounding events. An improved precise pounding algorithm was proposed to solve the dynamic equation of the bilateral pounding model. This algorithm is based on the precise integration method for solving the second-order dynamic differential equation and reduces the order thereof by introducing a new velocity vector and uses the series method to find the nonhomogeneous term. The system matrix is simpler, and the inversion of the system matrix can be avoided. On this basis, a multipoint earthquake-induced pounding response spectrum program was developed. A total of 18 seismic waves from Class II sites were selected, and the response spectra of 18 waves were analyzed using this new program. Furthermore, the effects of structural stiffness, mass, stiffness of contact element, pounding recovery coefficient, and peak ground acceleration (PGA) on the earthquake response spectrum were studied. Through the analysis of earthquake response spectra and a parametric study, the phenomenon of earthquake-induced pounding of bridges was clarified to the benefit of the analysis and engineering control of earthquake-induced pounding of bridges.

In order to evaluate the mechanical condition and working performance of a rigid frame bridge after reconstruction and extension, the mechanical performance of the bridge was analyzed by static load test. Static load test is the test of stress at each section of main beam under the action of partial load and medium load. The results show that, under the action of each load, the check coefficient of strain and deflection at each measuring point of the box girder does not exceed the standard limit value 1, the relative residual strain or deformation at each measuring point does not exceed the standard limit value 20%, the stress condition of the tested section of the box girder is normal, and the structure is under the normal stress state under the action of the test load.

In order to study the influence of prestress on cantilever deflection and construction linear control of continuous rigid frame bridge in construction stage, this paper introduces the significance of continuous rigid frame bridge’s linear control, the calculation principle and deflection influence analysis of vertical formwork elevation in cantilever construction. According to a specific continuous rigid frame bridge, this paper use the finite element software to simulate and calculate the deflection of prestress to the cantilever construction of continuous rigid frame bridge. The influence of friction coefficient between prestressed steel bundle and bellows and prestress loss on cantilever deflection and construction line control of continuous rigid frame bridge is also analyzed, furtherly brings out the solution to deal with the problems due to the change of prestress.

The author carried out dynamic load test research on a prestressed concrete rigid frame bridge. Under dynamic load, the ratios of the measured and theoretical frequencies of the first four vertical vibrations of the bridge were 1.081, 1.153 respectively. The corresponding measured damping ratios are 0.011, 0.010 respectively. The maximum dynamic coefficient of bridge sports car test is 1.049, and the corresponding dynamic strain increment coefficient is 0.059. The measured impact coefficient is between 0.012 and 0.049, which is basically equivalent to the design impact coefficient of 0.05.The test results show that the existing bridge works well under the test load, and the bearing capacity of the structure meets the requirements of the design load level.

Earthquakes can cause serious damage to traffic infrastructures, among which the impact on bridge structure is the most important. Therefore, in order to assess bridges serviceability, it is important to master their damage mechanism and to analyze its probability of occurrence under a given seismic action. Various uncertainties, like the location of epicentre of future earthquakes and their magnitudes, make this task quite challenging. We are also required to consider different earthquake scenarios and the damaged states of bridge components associated with those earthquakes. To suppress these difficulties, this study proposed a new method of performance-based seismic fragility and risk assessment for bridges. The proposed method included three steps: (1) performance-based seismic fragility estimation of a five-span continuous rigid frame bridge, (2) seismic hazard analysis for locations of the bridge, and (3) seismic risk analysis of the bridge. The proposed method that considered the performance of the bridge and the uncertainty in the location of the earthquake epicentre and magnitudes can provide valuable references for seismic-resistant design of multispan continuous rigid frame bridges in the future.

International audience; This work presents benchmark examples related to the modelling of sound absorbing porous media with rigid frame based on the periodicgeometry of their microstructures. To this end, rigorous mathematical derivations are recalled to provide all necessary equations, useful relations, and formulas for the so-called direct multi-scale computations, as well as for the hybrid multi-scale calculations based on the numerically determined transport parameters of porous materials. The results of such direct and hybrid multi-scale calculations are not onlycross verified, but also confirmed by direct numerical simulations based on the linearised Navier-Stokes-Fourier equations. In addition, relevanttheoretical and numerical issues are discussed, and some practical hints are given.

Analysis of the structural vibration, under the sound excitation is an important part of the quality assurance during the design process of devices. One of the most commonly used method is Laser Doppler Vibrometry (LDV). However, under the rapid fluctuations of temperature, structural resonances are shifted into the other frequencies. In such situation LDV method may be inconvenient, due to the scanning time. In this paper the authors proposed Chladni figures to modal analysis of the double-panel structure, excited by the loudspeaker enclosed inside the casing with a rigid frame. Double-panel structure has been proven to be particularly useful for noise and vibration reduction applications. Vision images, obtained during the experiments are converted to binary patterns, using GLCM matrix, and compared with simulations performed in ANSYS.

The current volume of freight traffic has increased significantly during the past decades, impacted by the fast development of the national transportation market. As a result, the phenomena of truck overloading and traffic congestion emerge, which have resulted in numerous bridge collapse events or damage due to truck overloading. Thus, it is an urgent task to evaluate bridge safety under actual traffic loads. This study evaluated probabilistic dynamic load effects on rigid-frame bridges under highway traffic monitoring loads. The site-specific traffic monitoring data of a highway in China were utilized to establish stochastic traffic models. The dynamic effect was considered in a vehicle-bridge coupled vibration model, and the probability estimation was conducted based on the first-passage criterion of the girder deflection. The prototype bridge is a continuous rigid-frame bridge with a midspan length of 200 m and a pier height of 182 m. It is demonstrated that the dynamic traffic load effect follows Gaussian distribution, which can be treated as a stationary random process. The mean value and standard deviation of the deflections are 0.071 m and 0.088 m, respectively. The dynamic reliability index for the first passage of girder deflection is 6.45 for the current traffic condition. However, the reliability index decreases to 5.60 in the bridge lifetime, accounting for an average traffic volume growth ratio of 3.6%.

Based on the idea of the matrix displacement method, this paper designs a program which can be used to solve the internal force of the continuous beam and rigid frame with MATLAB. It mainly demonstrates how to design a program to realize the matrix displacement method with MATLAB. In addition, some techniques are included in order to realize the correspondence between the manual calculation and the computer calculation, such as “Using lambda to locate”, “Crossing out rows and columns” and visual design. Therefore, based on the structural mechanics, combined with the principle of matrix displacement method, this paper shows the whole process from inputting the information of the rigid frame to solving the internal force of the rigid frame to outputting the bending moment diagram using MATLAB as the programming tool.

The authors proposed a reinforced concrete slab bridge with H-shaped steels which has high load-carrying capacity in order to reduce the construction cost. Our past study clarified that H-shape steels without stud dowel and concrete could compose hybrid section and static load was equally distributed each H-shaped steel in elasticity stage. Considering the described above it is possible to design this type of bridge as composite. Moreover it clarified that the cyclically loaded this type bridge has the high fatigue capacity and load-carrying capacity as same as the statically (non- cyclically) loaded that bridge. As next step the authors proposed a reinforced concrete slab rigid frame bridge with H-shaped steels in order to reduce the maintenance cost and to increase seismic performance. Especially the rigid connection method of H-shaped steel and re-bar in the abutments was proposed. Then the static loading test was carried out to grasp load-carrying capacity. As the results of the experiment destructive behavior of the reinforced concrete slab rigid frame bridge with H-shaped steels was clarified and also the validity of the connection method was clarified.

Robots for underwater exploration are typically comprised of rigid materials and driven by propellers or jet thrusters, which consume a significant amount of power. Large power consumption necessitates a sizeable battery, which limits the ability to design a small robot. Propellers and jet thrusters generate considerable noise and vibration, which is counterproductive when studying acoustic signals or studying timid species. Bioinspired soft robots provide an approach for underwater exploration in which the robots are comprised of compliant materials that can better adapt to uncertain environments and take advantage of design elements that have been optimized in nature. In previous work, we demonstrated that frameless DEAs could use fluid electrodes to apply a voltage to the film and that effective locomotion in an eel-inspired robot could be achieved without the need for a rigid frame. However, the robot required an off-board power supply and a non-trivial control signal to achieve propulsion. To develop an untethered soft swimming robot powered by DEAs, we drew inspiration from the jellyfish and attached a ring of frameless DEAs to an inextensible layer to generate a unimorph structure that curves toward the passive side to generate power stroke, and efficiently recovers the original configuration as the robot coasts. This swimming strategy simplified the control system and allowed us to develop a soft robot capable of untethered swimming at an average speed of 3.2 mm/s and a cost of transport of 35. This work demonstrates the feasibility of using DEAs with fluid electrodes for low power, silent operation in underwater environments.

Arslan, Mehmet Emin/0000-0002-7582-638X WOS: 000466999500078 The main purpose of this study is to examine the behavior of the brick masonry and infill walls under cyclic horizontal loads, irrespective of reinforced concrete frames. For this purpose, the test walls, which are produced as non-plastered (plane), two side plastered and two side plastered and strengthened with zinc coated steel wire mesh by using vertical and horizontal hollow brick walls were tested in a rigid hinged steel loading frame under lateral cyclic loading. The findings were evaluated in terms of load carrying capacity, ductility and energy dissipation capacities. The tests carried out showed that the expected increases were provided any type of plastered walls in terms of stiffness with respect to the reference non-plastered walls. Besides this, wired mesh used in plastered walls increased significantly the ductility and consequently the energy dissipation capacity of the walls by maintaining wall integrity in an advanced stage of the loading. Also, both hollow brick and vertical brick infill walls strengthening with wired mesh increase load carrying capacity of the wall test specimens. Load carrying and energy dissipation capacities of wire meshed specimens almost five times more than those of plane test walls. (C) 2019 Elsevier Ltd. All rights reserved.

A fully integral bridge that is restrained at both ends by the abutments has been proposed to form a monolithic rigid frame structure. Thus, the feasible horizontal force effect due to an earthquake or vehicle braking is mainly prevented by the end-restraining abutments. In a recent study, a fully integral bridge with appropriate end-restraining abutment stiffness was derived for a multispan continuous railroad bridge based on linear elastic behavior. Therefore, this study aims to investigate the nonlinear behavior and seismic capacity of the fully integral bridge and then to assess the appropriate stiffness of the end-restraining abutment to sufficiently resist design earthquake loadings through a rigorous parametric study. The finite element modeling and analyses are performed using OpenSees. In order to obtain the force-deflection curves of the models, nonlinear static pushover analysis is performed. It is confirmed that the fully integral bridge prototype in the study meets the seismic performance criteria specified by Caltrans. The nonlinear static pushover analysis results reveal that, due to the end-restraining effect of the abutment, the lateral displacement of the fully integral bridge is reduced, and the intermediate piers sustain less lateral force and displacement. Then, the sectional member forces are well controlled in the intermediate piers by a proper application of the end-restraining abutments.

CNC machine tools are currently predominating in the machine-building industry. Generally, these machine tools are equipped with control systems supplied by the world's leading manufacturers, such as Siemens, Fanuc or HeidenHein, and are very expensive. In parallel, many cheap amateur and semi-professional CNC machine tool solutions are being developed. Below, a CNC milling machine of welded construction is described, which is intended to be, at the same time, a test stand. The design of the milling machine is based on steel closed sections of a large cross-section and a big wall thickness. This has allowed a rigid frame structure to be obtained. To obtain high displacement accuracy, high-accuracy profiled rail slideways have been used, along which pre-stressed linear ball bearings move. The machine tool has been furnished with a fourth numerically controlled axis, which is demountable.

This research explores a new realm of soft robotic materials where the stiffness magnitude, directionality, and spatial resolution may be precisely controlled. These materials mimic biological systems where localized muscle contractions and adjustment of tissue stiffness enables meticulous, intelligent movement. Here we propose the use of a low-melting-point (LMP) metal lattice structure as a rigid frame using localized heating to allow compliance about selectable axes along the lattice. The resulting shape of the lattice is modeled using product of exponentials kinematics to describe the serial chain of tunably compliant axes, this model is found to match the behavior of the physical test piece consisting of a Field’s metal (FM) lattice encased in silicone rubber. This concept could enable highly maneuverable robotic structures with significantly improved dexterity.

International audience; Due to the manufacturing process, some fibrous materials like glasswool may be transversely isotropic (TI): fibers are mostly parallel to a plane of isotropy within which material properties are identical in all directions whereas properties are different along the transverse direction. The behavior of TI fibrous material is well described by the TI Biot's model, but it requires to measure several mechanical parameters and to solve the TI Biot's equations. This paper presents an equivalent fluid model that can be suitable for TI materials under certain assumptions. It takes the form of a classical wave equation for the pressure involving an effective density tensor combining both limp and rigid frame behaviors of the material. This scalar wave equation is easily amenable to analytical and numerical treatments with finite element method. Numerical results, based on the proposed model, are compared with experimental results obtained for two configurations with a fibrous material. The first concerns the absorption of an incident plane wave impinging on a fibrous slab and the second corresponds to the transmission loss of a splitter-type silencer in a duct. Both configurations highlight the effect of the sample orientation and give an illustration of the unusual TI behavior for fluids.

Taking the curved continuous rigid frame bridges (CRFBs) with high piers as research object, the construction stability of four different styles of main piers were analyzed by finite element (FE) method in three construction stages including the segment 0 stage, largest cantilever stage, and finished bridge stage. Rules governing the stabilities of bridges with various pier styles, height, and slenderness ratio were established. At different construction stages, pier type and pier height affect structural stability differently. Wind loads have little influence on structural stability at any construction stage, and accidental events influence the stability of bridges more than normal construction loads. There is a nonlinear power relationship of fixed functional type between the stability safety factor (SSF) and slenderness ratio in all four pier styles; this power relationship can be used to predict the stability of a new pier.

Taking the three-span pre-stressed concrete continuous rigid frame bridge as an engineering example, MIDAS Civil was utilized to establish a spatial finite element model and the interaction between pile foundation and the soil was simulated by equivalent soil spring. In addition to analyzing shearing force, bending moment and stress of the primary beam's characteristic section under different loads, a response spectrum method and time history analysis were adopted to conduct seismic response analysis respectively. In this case, performance of the bridge could be comprehensively evaluated. Relevant analysis results indicate that internal force of the large-span pre-stressed concrete continuous rigid frame bridge is mainly induced by gravity and pre-stress of the structure; section stresses of the primary beam satisfy the corresponding specification and structural safety can be achieved in a state of operation. Moreover, computed results obtained by the response spectrum method is more conservative than those of the time history analysis. In terms of continuous rigid frame bridge, different seismic directions should be taken into consideration during structural seismic analysis at different construction stages.