This paper presents main aspects of the structural design of Sichuan University Multi-Discipline Cross-Integration Platform and Art Education Center,including foundation,basement,structural arrangement,seismic fortification measures,structural analysis results and performance-based seismic design.The building characterizes complex shape,connected structure,large span and long cantilever.Critical issues of the structural design and methodology are presented with abovementioned characters. Analysis method and conclusions may be useful to similar projects.

With development of the construction industry,construction of large span steel structures in our country started extensively in our country.On the one hand,this promotes improvement of large span steel structural design,on the other hand, it also highlights some common design problems in the steel structures.This paper discusses basic steps for large span steel structural design and research.This study also discusses the design process of elastoplastic analysis in structural design and effect of structural form on ultimate bearing capacity,and summarizes frequently asked questions in the structural detail design about the selection of bearing types and the influence of the joint detail on mechanical properties of the structure.Finally,this paper presents design considerations and improvement measures to these common problems.

Li Zijian Art Museum is a mega-steel-structure with mega-frames and braces.A ring atelier is supported by 17 main trusses suspended by 3 mega-columns.The main trusses are connected as a whole by an inside ring truss and an outside ring truss.The largest span along the ring atelier is 44.6 meters.Based on the performance-based design method,the performance objectives and design specifications of key components are proposed.Performances of the structure are verified under different levels,including elastic analysis under frequent earthquake,unyielding verification and elastic analyses under medium earthquake and elasto-plastic analysis under rare earthquake.The results show that a few plastic hinges formed in some braces and the first layer of the mega-columns.Good seismic behavior performed and seismic indices of key components can satisfy the predefined performance requirements.

Taken a super high-rise frame-core wall structure as an example,comprehensive optimization of the original structural design calculation parameters,structural loads,walls,columns,beams,plates,roof steel structure brackets and raft foundation was conducted,where the structural stiffness,weight and cost were set as control objectives,while meeting the structural specifications and transfinite review requirements.Comparison of the stiffness,seismic performance and cost between the original design and the optimized one was conductedby PKPM software.The results show that all the indicators meet the specification requirements,and benefits such as reduced structural weight,reduced earthquake action, more reasonable stiffness distribution,increased ductility and structural safety,increased indoor space,shortened construction period and reduced construction cost of 22 million 946 thousand and 800 yuan profit.

Aspect ratio for tower transfinite structure can lead to insufficient capacity to resist capsizing and stiffness to resist lateral force, lack of tensile strength for wall limb.One can solve the problems by changing the structural plane arrangement,connecting the bottom of adjacent low and high towers to form an L-shaped combined tower at the bottom of the tower,and the equivalent resistance to the capsizing lever at the bottom of the structure can be increased.According to a number of plane and vertical irregular situations induced by the combined towers,corresponding seismic performance objectives are set up.Stress analysis on the floor weak parts and parts with contracted facade under frequent earthquakes was conducted. Stress analysis on the floor under medium earthquake static elasto-plastic pushover analysis and dynamic elasto-plastic time history analysis of the tower under rare earthquake were also conducted to study the nonlinear properties of the structure.The deformation mode,plasticity development and damage of the members as well as the elasto-plastic behaviors of the whole structure were investigated.According to the calculation results and the elasto-plastic behaviors of the structure, seismic performance of the structure was evaluated and instructions for the follow-up structural design were given.

The Pi-he main channel aqueduct structure adopts a truss-type beam-arch composite system with main span of 110m. The corrugated steel webs are used for the water retaining plate on the sidewall of the trough body. For corrugated steel web structure, the current researches show that the method of building 3D refined plate shell model is mostly used to analyze the structural performance, which is cumbersome and with low computational efficiency. Therefore, based on the principle of stiffness equivalence, an equivalent analysis method is proposed to simplify the three-dimensional corrugated steel web into a two-dimensional orthotropic steel plate. Firstly, a 3D refined model of corrugated steel web and an orthotropic steel plate model using the equivalent method for aqueduct structure were established. Then the structural static performance analysis was carried out. Finally, the static response and relative error of the two models were compared. The results show that the calculation results of the equivalent orthotropic plate model are in good agreement with that of the 3D refined plate shell model, and the equivalent method has high accuracy and reliability. This study can provide a simple method for the analysis of corrugated steel web structure and improve the calculation efficiency.

The structure systems and existing problems of traditional rural residence in China are summarized,several precast housing systems which are suitable for the new rural construction are enumerated,the factors that prevent the development of rural precast house and the reasons for increased cost of it are analyzed.Through the investigation of the current situation about rural housing in Guanzhong area of Shaanxi province and the demand for housing construction of farmers,some suggestions about precast building in the construction of rural residence are presented,which provide a reference for the construction of new rural in china.

The response displacement method is widely used for seismic design and analysis of underground structures,however,it has several shortages and limitations as a simplified method.Based on the basic principles of the response displacement method,a novel calculation method,named response shear stress method,is proposed with the soil-structure model in this paper.Both the soil-structure interaction and the shear stress distribution of soil layers can be easily and accurately incorporated into the proposed method.Because the uniform shearing interaction between the soil and structures is the principal reaction under seismic loadings,the seismic action can be assumed as the shearing force of soil layers,and then imposed on the soil-structure model.The seismic responses of the structure are finally obtained by the quasi-static method.The dynamic time-history analysis method is taken as the benchmark model to calibrate the proposed method.The optimum dimension of the soil-structure model used in the presented method is determined by comparison with the benchmark model.Furthermore,the validation of the proposed method is verified and approved to be applied for different geological conditions and structural section configurations.Results show that,the proposed response shear stress method could achieve consistent results with the benchmark model when the boundary dimension is over five times the structural diameter or height.Compared to the response displacement method,the response shear stress method could be widely applied in seismic analysis with different ground conditions and structure types.In addition,the design process of the proposed method is simpler and convenient,which provides a novel method for seismic design and analysis of underground structures.

The stiffness matrix of the curve beam coupled by shear, bending and torsion was derived based on the dynamic discrete model of a single-span curve beam with constant curvature. The algorithm was written with reference to the concentrated mass matrix of the curved beam and the characteristic equation of the motion equation of the multi-degree-of-freedom system, and the natural frequencies and modes of each order were calculated. By comparing the respective integration methods of the stiffness matrix and the finite element stiffness matrix, the distribution form of the stiffness matrix of curved beam structure is intuitively shown. the characteristics of the two stiffness matrices were discussed. The calculation results of the stiffness matrix of this article involved in the modal analysis and the finite element numerical simulation results were compared and analyzed. The results demonstrated that the former approaches the true solution faster than the latter, though the calculated natural frequencies of the middle and low orders were in good agreement. However, the finite element method has certain errors in the accuracy of solving high-order rotational modes. The written calculation program could provide reference for accurately solving the modal of curved beam structure in actual engineering.

Friction-sliding isolation system (FIS) is a common type of widely used isolation technique for building retrofitting,which has the advantages of better seismic response mitigation effects and simpler construction details.However,development of FIS is limited by its drawback of the large displacement of the seismic isolation layer under rare earthquakes with the significant residual post-earthquake deformations.A combined friction-sliding isolation system (CFIS) is designed based on the combined sliding isolation performance to fit the requirements of retrofitted timber buildings on soft ground,which is mainly composed of elastic sliding bearings,with additional laminated thick rubber bearings (TLRs) and viscous dampers.A very good isolation efficiency of the elastic sliding bearings with wide range of frequency is proved,and the residual deformation and the maximum displacementof the isolation layer is considerably reduced respectively through TLRs and viscous dampers.The conception and calculation method of the equivalent natural periods of the isolated structure with CFIS under various seismic ground motions are proposed,and the mechanical properties of CFIS are analyzed.With good isolation efficiency of CFIS,this system will be of reference value for similar seismic isolation retrofit projects in the future.

Aiming at the problem of sunshine temperature difference effects of curved box girder highway bridges, based on the brief introduction of the calculation method of box girder temperature boundary,the calculation program of sunshine temperature difference temperature of box girder bridges considering the influence of azimuth of bridge axis is developed based on Visual C++. A curved box girder bridge is taken as an example to calculate the sunshine temperature difference effect, and compared with the current design code for highway bridges method. The results show that,due to the joint effects of curvature and azimuth of the bridge axis, the curved box girder bridge will have radial and axial displacements at the same time under the effect of sunshine temperature difference,and the vertical displacement direction of the middle of the central span and the middle of the side span is opposite. The stress distribution on the top of main deck changes little along the axis of the bridge, while the stress distribution at the bottom of the main deck changes relatively large along the axis of the bridge. Except for the calculation results of the stress at the top and bottom deviated from the calculation results according to the code method, the results obtained by the calculation method of this paper, namely the displacement,the torsion angle and the internal joint stress of the section,are generally consistent with the calculation results according to the code method.

In Response displacement method,two methods are widely used to obtain the ground deformation:the equivalent linear method and the velocity response spectrum method.In order to investigate the ground deformation mode under seismic loading,the program,SHAKE91 code based on the equivalent linear method was employed to obtain the ground deformation under the scenarios of different ground conditions and various earthquake intensities.The results of SHAKE91 are regarded as the benchmark.For the purpose of adaptability validation,results obtained from the velocity response spectrum method were compared with the results from the benchmark.Results show that the ground deformation mode is expressed in the shape of a standard sine curve,when the soil layer is uniform and the shear wave velocity is constant, and in that case the velocity response spectrum method is validated; inversely,when the soil consists of layers with significantly different shear wave velocities,the ground deformation mode becomes irregular,and the velocity response spectrum method is no longer validated and could not be applied in seismic design of underground structures.

Firstly,the traditional stochastic mode imperfection method suitable for grid shells is improved to make it more suitable for the analysis of radiant string beam structures. The iterative method is used to perform morphological analysis of the radiant string beam string structures to obtain the initial state,and then the advanced stochastic mode imperfection method is used to perform nonlinear stability analysis of the structures. The effects of rise-to-span ratio, defect amplitude and pretension on the stability of the radiant string beam structures are studied. Finally, the analysis results of the stochastic mode imperfection method and the consistent imperfection mode method are compared. The analysis results show that the initial imperfection will reduce the stability bearing capacity of the radiant string beam structures, and the larger the defect amplitude, the smaller the structural stability bearing capacity. With the decrease of the rise-span ratio, the stable bearing capacity of the radiant string beam structures gradually decreases. The stable ultimate load with the 95% guarantee rate gradually increases compared to the ultimate stable load of the perfect structure. Cables can effectively improve the stability of the structure's ultimate bearing capacity and reduce the structure's sensitivity to defects. The increase of the pretension can slightly reduce the sensitivity of the structure to defects. When the rise-span ratio is less than or equal to 1/10, the consistent mode imperfection method can be used to analyze the stability of the radiant string beam string structures.

Cable safety have great influence on operation and service life of bridge,Cables with broken wires become the main form of cable damage due to the effect of cable aging,corrosion and wire breaks. Based on the mechanical model for multilayered semi parallel wire cable with non-symmetric wire breaks, distribution of wires' axial forces, magnification factors of axial force and axial stiffness of cable are highly discussed by numerical calculation. Comparing with parallel model,results show that non-symmetric break lead to obvious non-uniform distributions of wires' axial forces, and that parameters affect the most to axial stiffness of cable are helix angle and inter-wire friction coefficient. The error is bigger while parallel model is applied,and the calculation results have proved to be unsafe.

In order to solve the problem of excessive transverse displacement of bridges supported by laminated rubber bearings under near-fault ground motions,nonlinear finite element models were established for a typical simply-supported bridge based on experimental data and taking into account of the sliding effect of laminated rubber bearings,and the hysteretic properties of reinforced concrete side retainers and X-shaped steel retainers.Using the ground motion records from the Wenchuan Earthquake and other typical near-fault ground motions,the effects of side retainer types,retainer strength and initial gap were investigated on the efficacy of displacement control methods.The results showed that the traditional reinforced concrete side retainers are not competent in controlling the displacement response of the bridge under near-fault ground motions despite the values of the strengths and gaps of retainers.With a same strength,the steel retainer plays a competent role in restraining the displacement response of the bridge,which indicates that the deformation and ductility capacity are crucial parameters for side retainers in controlling the displacement response of bridges.The existence of retainers amplifies the seismic response of the bridge piers.And when the retainers are stronger the amplification is more significant,which implies that the competence of retainers in controlling displacement introduces detrimental consequences for bridge piers.And hence,the strength of retainers calls for optimization when they are used as countermeasures for controlling displacement of bridges.

Adopting the “rigid body-MDOF” model,the basic equations of the pin-joined and rigid-joined system of the framed self-centering wall structure under lateral loading were established respectively with the cooperative work between the frame and self-centering wall taken into account.The analytical solutions of internal force and displacement responses were given and the mechanical behavior of the framed self-centering wall structure was investigated preliminarily.It is shown that the lateral displacement curve of the framed self-centering wall structure is linear along the height,which indicates that the story drift ratio remains constant along the height.After equipped with prestressed tendons and dampers,the overall stiffness of the framed self-centering wall structure are enhanced obviously and the shear force demand of the frame is lowered.The restraint provided by the coupling beams can also effectively reduce the responses of the framed self-centering wall structure under lateral loading.The overall performance of the framed self-centering wall structure under lateral loading ranges between that of the frame wall structure and the frame structure.

The roof ring-beam of the main stadium of Hangzhou Olympic Sports Center has complex construction and poor support condition.The traditional support frames are difficult to achieve the goal of reasonable function,cost optimization and schedule guarantee.A steel platform system of high-altitude bearing supported by the standard section of tower crane is proposed and designed.By comparison and analysis,theoretical analysis,finite element simulation and a series of research and calculation,the erection process of the supporting system technology,design methods,structural performance and construction are fully argued.Then the bearing system is applied to the actual project and the roof ring-beam construction is successfully completed.Finally,put forward some points of construction which can be used in future similar projects.

Most of the reticulated timber shells are connected by a semi-rigid connection between rigid and articulated joints.In this paper,a kind of bolt-steel-plate joint was selected to carry out the bending test of JD1 and JD2,and the load-displacement curve and the bending-moment curve are obtained.The number of bolts was changed to reflect different flexural rigidity.A multi-section beam model is established based on the experiment,and the theoretical value of the displacement is calculated according to the force method.The nonlinear finite element model of Beam189 is used to simulate the connection between the node domain and the bar.The analytical results are compared with the experimental and theoretical values to verify the rationality of the simplified model.Finally,the multi-section beam model is applied to the semi-rigid model of reticulated timber shell,and the effect of the joint stiffness on the ultimate bearing capacity of the shell is considered.

In order to adapt to the development and use of long-span steel structure,a new structural system of staggered-truss——steel shear wall is proposed,which is based on the hybrid staggered-truss system and is more advanced than it.Then four calculation cases with two different spans are established.Response spectrum analysis,nonlinear time history analysis and steel quantity analysis are carried on by sap2000.Finally,it comes to a conclusion that the new structure has a better seismic performance and economical value than the traditional one.

Environmental change has a direct impact on the ancient brick masonry.Taking the ancient bricks in Shanxi Province as an example to perform the laboratory test in investigating the compression damage of the bricks under freeze-thaw cycles in atmospheric environmental.The regulations of the cracks were analyzed using image processing techniques.The influences of the number in freeze-thaw cycles on compression features of the ancient brick masonry were furthermore examined.It shows that the width of cracks in the central part is less than that in other locations ;the crack load and failure load are larger than others as the number in freeze-thaw cycles reach to 20;when difference value between cracking load and failure load is larger than 190 kN,average of crack width is around 1.8 mm.The damages of the brick masonry in the first stage occur ahead of time significantly if the masonry beards the freeze-thaw cycles,and the damage percentage in the first stage is 35.16%,respectively.The results in the current study may be referable in analyzing the features on ancient brick masonry.

This paper presents an experimental study on elliptical hollow sections under combined compression and cyclic bending.A total of four specimens are tested,where the main parameters are cyclic loading directions and load ratio.The main focus of the study is on their failure mode,hysteresis response,skeleton curves,and ductility supply.The test results show that:local buckling,featured by outward bulges of the tube wall,is the governing failure mode of the specimens.Increasing the load ratio tends to compromise both the lateral load carrying capacity and ductility of the specimens.In addition,strong axis cyclic bending leads to higher lateral load carrying capacity but reduced ductility compared with the case of weak axis bending.

Studies were focused on the influences of shell load on the shell internal forces of hyperbolic cooling towers,and the influence surfaces of internal forces were employed in the illustration.It was found that the influence surfaces of latitude axial force,latitude moment and meridian moment show the striking local effect,or these internal forces are just influenced by the pressure around their locations.The influence surface of meridian axial force shows the minor local effect,or it would be influenced by the pressure along the shell height.The shear force and torque moment are between the former two conditions.Furthermore, the local effects are more profound in latitude than in meridian direction.Due to the latitude local effect of influence surfaces for all internal forces,the latitude distributions of wind pressure and internal forces show great similarities.

In this paper,the mechanical property and confining ability of quick-attachable steel-tie-column,which is applied to masonry fill walls,is studied.On the base of contrast test of steel-tie-column and concrete-tie-column,ABAQUS software was used to simulate the performance of the test prototype.The comparison between test result and finite element analysis shows that the simulated damage cloud image of the wall agrees well with the test result.By comparing the analysis data,wall displacement,steel-tie-column displacement and the stress of tie bar embed in wall,with the test results,the rationality of finite element model was verified.Test result and finite element analysis show the good of steel-tie-column,such as good integrity,little displacement and reliable connection with tie bar,which makes it available to tie the wall,avoiding wall overturning.Because steel-tie-column is convenient in construction and the construction quality can be effectively controlled,steel-tie-column has a good application prospect to replace concrete-tie-column.

Vertical irregularities of the infilled wall have adverse effect on frame structure.Three kinds of equivalent models of the infilled wall with vertical irregular arrangement were established by SAP2000 according to the equivalent diagonal bracing and comprehensive analysis was done in aspect of the overall displacement response and failure mechanism and so on.Results showed that vertical irregularities of the infilled wall easily led to highlight of structure weak story.Development of plastic hinge of the structure was restrained by the infilled wall to a certain extent. Vertical irregularities of the infilled wall would make the plastic deformation of the structure mainly occur in the weak story.Based on the above analysis,an improved solution to vertical irregularities of the infilled in models of the maximum seismic response was put forward and effectively verified by a pushover analysis.

The solar photovoltaic power generation has become an important part of the green energy development and utilization in the world.The cable structural system of photovoltaic power station has been focused because of many advantages.Wind can bring about the main load acting on the photovoltaic panels of photovoltaic power station.The two-dimensional Computational Fluid Dynamics (CFD) numerical simulation technology is adopted to analyze the wind load characteristics of arrayed photovoltaic panels.For two kinds of extreme conditions,which are the loaded cases of forward wind and backward wind,the wind load and its reduction characteristics are analyzed in the investigation considering the effects of the photovoltaic panel angle,distance between panels and height of panels.The analysis method and correlative conclusion are helpful to the structural strength design of photovoltaic power station.

In order to study the influence of corrosion on fatigue life of components and ensure the safety of old steel bridges,this paper introduces the fatigue tests on the discarded components from Zhejiang Rd.Bridge and following researches.The test data are analyzed to find out the corrosion effects on the fatigue life.An conservative curve and calculation formula for fatigue evaluation based on the test data are proposed.The results of the analysis indicate that the higher corrosion loss of thickness ratio is,the lower fatigue life will be.And the relationship between the former and the logarithm of latter is negative correlation.Conservative fatigue life reduction calculation rules and the method of calculating the equivalent fatigue details of corroded components is proposed.Finally,based on the Miner criterion,the fatigue life of corroded components is estimated.

Existing performance indices of self-centering capability for bridge columns mainly rely on the ratio between the restoring force of elastic units and energy dissipation force of elasto-plastic units.These performance indices require separate solution of restoring force and energy dissipation force,so it is difficult to extend them to practical columns.A single-degree-of-freedom flag-shape hysteretic model is selected as an example in which a bilinear elastic spring and a bilinear elasto-plastic spring are in parallel.A new performance index of self-centering capability is put forward.It takes into account the effect of the restoring force,the energy dissipation force and the post-yield stiffness on the self-centering capability.The performance index can be obtained from force-displacement hysteresis of columns.The new performance index and the quasi-static residual displacement are adopted to compare the self-centering capability of columns with unbonded prestressing strands.The results of quasi-static cyclic analyses and nonlinear time history analysis show that increasing prestressing force,decreasing the amount of longitudinal reinforcement and adopting scattered strand configuration can improve the self-centering capability in varying degrees.

Based on the research findings at home and abroad,and by referring to the low-strength concrete pile foundation treatment plan of Zhejiang Taizhou Jialichen Bridge,this article applies finite elements to analyze the impact of equal-length pile changes on the elimination of the bump at bridgehead and the secondary bump.The topological optimization is adopted to analyze the pile length and determine the required optimal pile arrangement for the bump at bridgehead and the secondary bump.According to the analysis,the equal-length pile can be adopted by the low-strength concrete pile to effectively alleviate the bump at the bridgehead,but it will also simultaneously lead to the secondary bump at processing sections and non-processing sections of the foundation.However,the topological optimization can introduce pile arrangement with an unequal length that not only reduces the bump at the bridgehead but also delivers a smoother transition between processing sections and non-processing sections to avert severe secondary bump.

For evaluating the seismic performance of RC columns strengthened steel wire,based on the test results of 27 circular RC columns strengthened with prestressed high strength steel wire under low reversed cyclic loading,and on the basis of selection of model input variable using the theory of grey correlation,the ductility of the radial neural network analysis model is established. Through prediction and research,the influence law of reinforcement column ductility is known about the axial compression ratio,steel wire spacing,prestressinglevel.The results show that the method can reflect the nonlinear variation between ductility and impact factors.When the shear span ratio is small,prestressing level in 0.6 as the cut-off point.When prestressinglevel is less than 0.6,the increase of the prestressing level is good for ductility.On the other hand, when prestressing level is greater than 0.6,the increase of the prestressing level will be adverse to the ductility.Evaluation results provide reference for engineering and seismic and optimization design.

The shear stiffness of corrugated steel webs is weaker than that of concrete webs, which will leads to a large shear deformation. Additional stress appears in the concrete slabs near supports of the bridge girder due to the restriction of shear deformation of corrugated steel webs by the end crossbeams. The quasi plane section assumption is not applicable in this case. Analytical solutions of concrete normal stress considering the shear deformation of steel webs were derived based on the theory of elasticity in this paper. The results indicate that the maximum additional stress of the top and bottom concrete slabs exists in the end section of the composite girder. The additional stress decreases to zero as increasing of the distance from end section, and the distribution length is about 0.6 times of the beam height, where the quasi plane section assumption is no longer applicable. The additional stress at the upper surface of the concrete slab is in tension,while the lower surface shows a compressive stress,with zero at the neutral axis. Maximum additional tensile stress occurs at the upper surface of the concrete slabs at the beam end, thus measures should be taken to prevent possible cracks of concrete in this region.

The base isolated structure of a multi-tower building with unified base-floor is analyzed and designed by YJK. The analysis results show that the base isolated structure can significantly reduce the earthquake action of the upper structure. With bearings and dampers reasonably used in the design, the torsion caused by the irregular structure plane can be reduced. Base isolation of multi-tower building is very suitable for use in high intensity areas. The main structure of the project has been basically completed. This paper can be used as a reference for the design of similar projects.

Based on the theory of elastic mechanics and corrosion mechanism of reinforcing steel, the critical corrosion amount of reinforcing steel for cracking of concrete cover was derived. Based on Faraday’s law, an analytical model for time to corrosion-induced cover cracking in reinforced concrete structures was established. The proposed analytical model was verified by comparing the analytical predictions with the experimental results. The main factors affecting the time to corrosion-induced cracking were analyzed. The analytical results show that the time to corrosion-induced cracking increases gradually with the increase of thickness of concrete cover thickness and elastic modulus. The time to corrosion-induced cracking decreases gradually with the increase in the volume expansion ratio of corrosion products, corrosion rate and tensile strength of concrete.

Combined with the actual project,use SAP2000 finite element software to establish a 5×5 span underground garage structure model without beams, comprehensively consider factors such as the thickness of the soil, the type of construction vehicles and the parallel situation,and determine the unfavorable layout of construction vehicles according to the principle of influence lines,and obtain construction vehicles,etc. The effect of uniformly distributed load is compared with the commonly used construction load of 5 kN/m² in the design.The results show that the equivalent uniform load of construction vehicles is mostly greater than 5 kN/m²,and the equivalent uniform load value of construction vehicles decreases with the increase of the cover soil thickness,and increases with the increase of the vehicle load.Comprehensively considering the equivalent uniformly distributed loads of the four construction vehicles,the recommended values for the equivalent uniformly distributed loads of the construction vehicles are put forward, and the results can be used as reference for engineering design.

The grouted sleeve connection is an important way to connect prefabricated components, and the quality of grouting is the key to ensuring reliable connection between components.Because the grouted sleeve connection is a concealed project, how to detect the grouting compactness has attracted widely attention. This paper first describes the mechanical properties of the grouted sleeve connection under different grouting states, and explains the necessity of detecting the grouting compactness. Subsequently, the existing detection methods are reviewed. The embedded steel wire drawing method, endoscope, ultrasonic method, impact echo method, X-ray detection are introduced and the principles, advantages and disadvantages are analyzed in detail. Meanwhile, the methods to detect the quality of sleeve grouting are suggested and the future development direction of grouted sleeve compactness detection is prospected.

A two-story multi-span unbonded prestressed concrete frame structure is split into several single-span frame structures and an additional layer is added in accordance with the need of reconstruction. Prestressed reinforcement in one direction will be fully cut off. Based on a variety of reconstruction and strengthening program comparison and selection,unbonded prestressed steel strand stress release and re-tension method is ultimately determined. Together with professional construction unit, the key technologies of the project is successfully completed. The construction monitoring shows that the deformation of the whole process is reasonable and controllable.It belongs to the green reconstruction project, along with good economic effect.

The plane and elevation of the project are irregular,belonging to complex overrun high-rise buildings. The main structure adopts frame-shear wall structure system,and the roof adopts steel structure locally.It's carried out seismic performance-based design. This paper describes in detail the seismic performance objectives,overrun and strengthening measures,linear elastic analysis,elastic time history analysis,component design,floor stress analysis and elastic-plastic analysis, steel roof design and floor design. Through the analysis, the project can achieve the expected seismic performance objectives,and the seismic performance is good. The specific analysis methods and conclusions can be used for reference in similar engineering design.

Henan science and technology museum is a tall building structure beyond the code limits with several types of irregularities,such as torsional irregularity,irregular plane,existing holes,size mutation,crossing column,inclined column, interlayer and component conversion.According to the seismic performance level, elasto-plastic dynamic analysis under rare earthquake is conducted. Damage of key structural members such as column, the shear wall,large cantilever steel truss, large span steel truss is analyzed, which provides calculation basis for performance-based design of subsequent construction drawings.

For engineering projects in Indonesian, it is normal to design them according to Chinese standards and in the meanwhile meeting the requirement of obligatory term of Indonesian mandatory specification. The understanding of Indonesian seismic design code and transformation with Chinese seismic design code are the difficulties in the design of Indonesian engineering projects. In this paper, seismic resistant design method, the earthquake force and other aspects between Indonesian and Chinese design code are compared. Finally their similarities and differences are sumarized.

Based on the load transmitting mechanism analysis for grouted sleeve connections under tension, it is found that the compressive strength of grout is a crucial factor effecting mechanical behaviors of the connection. An analysis with Abaqus software was conducted to simulate the connection under incremental tension as following steps： firstly, the simulation was carried out to build a way to distinguish failure patterns of the connections under ambient temperature by developments of the interfacial damage between grout and steel rebar, which develops an simulation method for grouted sleeve connections under incremental tension; then, it is suggested that the crucial temperature of failure pattern change should be 400 ^oC for the heat-damaged connections with compressive strength of 85.1 MPa and embedment length of 7.7 times rebar diameter under incremental tension. In addition, the phenomenon of steel rebar fracture outside the sleeve is captured and the decreased part of the load versus displacement curve is obtained from the results of connection simulations in this paper, which are beneficial to distinguish the failure patterns of such connections. All of these findings are important to enhance the reliability of grouted sleeve connections under incremental tension.

The deviated pre-tensioned girder with discounted reinforcement avoids the shortcomings of post-tensioned prestressed concrete girder in tunnel construction technology and durability, and improves the mechanical adaptability of prestressed concrete structure, so it has a broad application prospect in bridge engineering. In practical engineering, the concept of load transverse distribution coefficient is often used to simplify the spatial multi-beam system into single beam system for analysis and calculation. However, with the increase of span, bridge width and the adjustment of beam spacing, this simplified calculation method will have a significant impact on the spatial stress state of the actual structure. Therefore, this article established the three-dimensional finite element model of I-beam, this paper studies force behavior of I-beam, through comparing all kinds of load transverse distribution coefficient calculation method and the error of the actual space force, put forward the reasonable and applicable method by studying the transverse beam spacing on force of main girder space, put forward reasonable design reference.