Chinese construction industry has made remarkable achievements in technological progress and engineering practice. The comprehensive strength of construction enterprises has been continuously enhanced, with leading technological advantages and engineering practice in many aspects. A relatively perfect national engineering construction standard system has also been established in China. This paper studies the current engineering construction standards in the field of high-rise buildings in China, and establishes the Hall three-dimensional model of the design and construction technical standards. Through typical case studies of structural seismic design in high-intensity areas and super-thick raft foundation construction in desert areas, the highlights and experience have been analyzed for the application of Chinese high-rise building design and construction standards in international contract projects, and the significant impact of the selection of the standard system has been explored on project quality, construction organization, project progress and cost. It is indicated that China has accumulated rich experience in high-rise building design and construction in project planning and management, design optimization, building material development, construction technology improvement and innovation. The adoption of China's engineering construction standards is beneficial to improving the performance of Chinese enterprises in overseas projects and promoting the high-quality development of Chinese foreign contracting business.

The assessment of post-earthquake damage and seismic performance level of buildings is key process of performance-based seismic design. To solve the problem of the lack of an evaluation indicator for the earthquake-induced damage of double skin composite shear walls （DSCWs）, an experimental database including 37 flexural composite wall specimens under hysteretic loading tests is made in this paper. Based on the existing modified two-parameter Park-Ang damage assessment model, the empirical expression of the combination coefficient β about the design parameters （axial compression ratio, shear span ratio, section length-width ratio, steel content ratio, etc.） of the DSCW is established. Based on the seismic design concept in Chinese code that three-level performance target and two-stage seismic design, the damage states of the DSCWs can be divided into four levels： basically intact, slightly or moderately damaged, severely damaged, and failure, according to the feature points of the skeleton curves. The critical values of the corresponding damage indices are 0.086, 0.517, and 1.020, respectively. The research results of this paper can provide a necessary basis for the earthquake-induced damage evaluation, performance-based seismic design, and post-earthquake reinforcement of the DSCW structures.

Concerning the orthotropic steel bridge decks under above-deck explosions, a numerical simulation study based on steel plate explosion tests was conducted. The damage mechanism of the steel bridge deck of Taizhou Yangtze River Bridge was analyzed under explosions of five threat types specified by the Federal Emergency Management Agency （FEMA）, and the damage modes of different components of the bridge deck were revealed. The main conclusions are as follows. In all explosion scenarios, petal-shaped openings on the top plate, fracture and tearing of U-ribs, and plastic deformation of cross beams were observed. For scenarios with larger explosive charge （1 814 kg TNT, 4 536 kg TNT, and 13 608 kg TNT）, the failure modes of the bridge deck also include outward bending, local buckling, and fracture of cross beams, fracture of the U-ribs, and openings on the bottom plate. In scenarios with smaller explosive charge （227 kg TNT and 454 kg TNT）, the main energy consumption mechanism of the bridge deck was the top plate and top plate U-ribs, accounting for over 70% of the total energy consumption. In scenarios with larger explosive charge, the main energy consumption mechanism of the bridge deck involved the top plate, top plate U-ribs, cross beams, bottom plate, and bottom plate U-ribs, accounting for over 90% of the total energy consumption.

Prefabricated concrete building is a kind of green environmental protection building which can improve production efficiency and save energy. In order to study the seismic performance of prefabricated concrete bolt welding and Z-shaped joints, this paper carries out low-cycle reciprocating load tests on middle joints, observe the failure of specimens, and analyze the load-displacement hysteretic characteristics, ductility, stiffness and energy dissipation capacity of middle joints. The test results show that the hysteretic curve of the specimen is full in shape and has significant slip and pinch phenomena, and the ductility coefficient of each joint meets the requirements of the code for displacement ductility and has good seismic performance. The connection mode of joints has a great influence on the stiffness degradation of joints, and the joints of fully fabricated concrete frames have good deformation performance and anti-collapse ability under seismic load.

With the development of high-rise building related technology and the improvement of living standard, while the seismic safety of high-rise buildings being focused on, greater demands are put forward for their comfort under wind loads. Evaluation of building comfort is subjective and uncertain, which needs a huge amount of literature review and analysis to develop more appropriate comfort evaluation standards. In this paper, based on the existing codes and engineering cases of high-rise buildings, the comfort standards and evaluation methods worldwide were systematically sorted out and their applications were summarized. With the analysis of the standards and cases, the problems and deficiencies in the existing comfort evaluation standards in China are proposed. Then the solution and future research directions are put forward. It is expected to provide the reference for the development of building wind-induced vibration comfort standards for high-rise buildings in China.

In this work the temperature of two side walls of a subway station under construction in Shenzhen was monitored, and then the temperature fluctuation characteristics caused by the heat of hydration in the large-volume concrete structure of the side wall of the subway station were analyzed. Then the phenomenon of concrete interior and surface, surface and environment, cooling rate and other phenomena was further analyzed, and the temperature change law of concrete was obtained. ABAQUS finite element software is used to simulate the whole temperature change process. A three-dimensional stress field-temperature field coupling model of the side wall was established, and the result was compared with the experiment data to verify its reliability. The stress state of concrete was analyzed, the principle of temperature stress was verified, the stress concentration of the subway side wall was predicted, and relevant measures to prevent cracks was proposed.

Based on the theory of one-time sampling inspection, balancing the risks of the manufacturer and the user, and considering the protection of the interests of the manufacturer, it is proposed that the evaluation coefficient k for strength average value should be corresponded to 90% the equivalent assurance rate （0.9 Quantile value） for both the known standard deviation method and the unknown standard deviation method, and the sampling scheme when the standard deviation is unknown is determined based on Bayesian theory. When the sampling size is very small, the acceptance criteria of non-statistical method is established based on the average quality standard deviation, and the minimum value acceptance criterion is proposed according to the theory of one-time sampling inspection. Using the concept of Bayesian method, the samples in the previous inspection cycle and the current inspection cycle are combined to expand the sample size and improve the test efficacy of the acceptance criteria with known standard deviation. Bayesian method is adopted to comprehensively consider the average quality standard deviation and the standard deviation of measured samples to improve the test efficacy of acceptance criteria of non-statistical method. The acceptance criteria proposed in this paper have a more clearly statistical basis. The unified equivalent guarantee rate is used to keep the test efficacy close to each other, and the Bayesian theory is used to unify the various methods into the statistical method with unknown standard deviation. The case analysis shows that the acceptance criteria proposed in this paper are slightly stricter than those in GB/T 50107—2010, but the variation range is within the acceptable range; after adopting reasonable prior standard deviation, the Bayesian improved method proposed in this paper can obtain scientific and reasonable evaluation results.

Tunnel engineering accounts for a large part of the road and railway projects in the dangerous mountains in southwest China. This area has large tunnel burial depth, complex geological conditions and frequent seismic activities. There are several engineering problems with small angle crossings between tunnel engineering and active faults. In addition, near-field earthquakes have different influences on surrounding rocks with different burial depths. Therefore, near-field earthquakes of active faults have significant adverse influences on the smooth construction and safe operation of tunnel engineering. Therefore, based on the impact of multiple disastrous earthquakes at home and abroad on tunnel engineering, the influence rules of historical earthquake magnitude on the damage of surrounding rock （surrounding rock burial depth, lithology and grade） of tunnels passing through the seismogenic fault are analyzed and summarized. Combined with the characteristics of active faults, the ground motion records that can reflect the regional fault characteristics and pulse characteristics are obtained. Finally, the finite difference software FLAC3D is used to study the influence of the active fault near-field earthquake on the surrounding rock of deep tunnel engineering. The results show that the tunnel surrounding rock is more stable with the increase of tunnel buried depth, which can restrain the plastic deformation of tunnel surrounding rock. The trend of maximum shear stress and maximum principal stress under different ground motions is basically the same, and the stress of tunnel surrounding rock in fault section is greater than that in ordinary section. The surrounding rock of Grade IV and below has a great displacement and stress response when the depth of tunnel is 200m and PGA is larger than 0.3g. The response level increases with the increase of PGA, and there is a large increase of nearly 50% in the process of PGA from 0.2g to 0.39g. This process is the main process of tunnel plastic deformation, and the area of plastic zone gradually increases with the increase of PGA. Therefore, the influence of near-field earthquakes should be carefully considered in deep-buried tunnels through active faults. The research results can provide technical support for seismic optimization design of tunnel.

This paper presents an experimental study on the self-healing effect of Engineered Cementitious Composites （ECC） under various conditions. First, specimens were fabricated using two different categories of fibers, and subjected to uni-axial tensile loading to reach different levels of pre-damages （non-linear strain）. Then the specimens were treated in different curing conditions for self-healing. Finally, a series of tensile tests were conducted on the self-healed specimens to evaluate changes in peak tensile strength, tensile strain capacity, tensile modulus and etc. The test results shows the damaged ECCs after healing treatment restored their tensile strength, tensile strain capacity to a certain degree and partial tensile modulus. The damage level, fiber category and curing condition have significant effects on the mechanical properties of ECC after healing.

As a novel structural system, the continuous rigid frame bridge without bearings has the advantages of good integrity and no requirement for replacement and maintenance of the bearings. However, the pier-beam connection joints of this type of bridges are complex and prone to damage and destruction under seismic excitation, while the cross-section of girders are substantially greater than the pier cap beam. To date, seismic performance of such joints is scarcely investigated around the world. Utilizing a 4×40m continuous rigid bridge without bearings in a standard section of an intercity railway as prototype, quasi-static tests were conducted on a 1/3-scaled connection joint model, to investigate the damage mode, hysteretic energy dissipation characteristics, and ductility capacity, as well as the failure mechanism under closing and opening bending moment. The observed results show that at the beginning of the test loading, horizontal cracks were mainly generated at the loading surface of the pier, and then gradually extended through, with fewer cracks developing at the diagonal edges of the joint and girder. As the loading displacement increases, cracks with small width gradually appeared at the diagonal side. Since the longitudinal reinforcement of the pier extended into the joint is only transversely designed with tie bars and no hoops, the significant arch damage was observed for the concrete at the top of the joint when subjected to closing moment. The force-displacement hysteresis curve was observed with small area with severe pinch effect. Although the longitudinal reinforcement at the top of the pier yielded when the joint was damaged, the ductility capacity was limited. Under the closing moment, the skeleton curve did not contain an obvious yielding plateau, and the lateral force experienced a sudden drop after reaching the peak, indicating the damage of the joint. Finally, based on the damage mode and damage mechanism, the reinforcement configuration of the side pier-main beam joint is suggested in conjunction with the AASHTO code.

In order to investigate the dynamic response of the airport taxiway base under the combined excitiation of aircraft taxiing load and underpass subway running load. Based on the real-time monitoring of a taxiway in a coastal soft soil airport, acceleration sensors were placed near the subway line crossing the taxiway to obtain the dynamic response of the taxiway. The response signals of long and short period frequencies corresponding to subway loads are obtained by separating the response signals, and the main frequencies of the dynamic response of subway and aircraft are separated by comparing the amplitude of the long and short frequency signals in the frequency domain. The results show that the main frequency of dynamic response of aircraft is 5‒30 Hz, and that of subway is 30‒60 Hz. The dynamic response produced by the aircraft taxiing load to airport runway is more than 6 times that produced by subway crossing.

The pushover analysis has the advantages of being easy to operate, having low computational costs, and being able to describe the overall nonlinear behavior of structures well. It is an engineering practical analytical method worth promoting and applicable for seismic performance-based design of general multi-story and high-rise building structures. However, this method has limitations such as difficulty in considering the influence of higher modes, significant differences in structural responses under different pushover force distribution patterns, and errors introduced by single-degree-of-freedom equivalence, which restrict its application in complex and irregular high-rise building structures.This paper considers the contribution of both fundamental and higher modes to the seismic response and combines the modes corresponding to sensitive modes into a final pushover force distribution pattern. This method is used to analyze the nonlinear seismic response of an oversized podium offset single-tower super-high building structure and is compared with the results of dynamic nonlinear analysis. The results show that the proposed method has good accuracy in predicting both the overall response of the structure and the yielding damage patterns of local components, with the additional benefits of high computational efficiency and strong applicability.

The rebound method has the advantages of no damage to the structural components, a large number of samples and flexible layout of the test area. However, the mean value and variance of the inspected strength may have a large deviation, so the accuracy of the strength characteristic value of the inspection batch estimated by the sampling inspection by variables is poor. According to the principle of single sampling inspection by attributes, based on the analysis and comparison of sampling characteristic curves, the estimation method of characteristic value of concrete strength of inspection batch is established considering that the acceptance probability of 0.1 unqualified product rate is 50% （the confidence level is 0.5）. The comparison of sampling characteristic curves and case analysis show that the estimation results of the proposed method is basically equivalent to that of sampling inspection by variables based on Bayesian method. Suggestions are put forward for optimizing the layout of rebound test area when evaluating the strength of test batch concrete, as well as the core drilling correction method for inspection results of rebound method by sampling inspection by attributes. The proposed method has the characteristics of accurate probability definition, avoiding the assumption of strength distribution type and variance calculation, and reducing the number of core drilling checks. It can be used in engineering quality compliance assessment and existing structure safety assessment.

A crack detection method for cylindrical members based on binocular stereo vision and spatial projection restoration is proposed. By this method, the image point of the crack edge on the image plane of the left camera is selected as the projection point, and the side surface of the cylindrical member is selected as the projection cylinder surface. Based on the obtained world coordinate of the projection point and the equation of the projection cylinder surface, the world coordinate of the actual crack edge point can be obtained by calculating the intersection of the line connecting the coordinate origin and the projection point and the projection cylindrical surface. In this way, the spatial shape of the crack can be restored, and further, based on this, the characteristic value of the crack can be detected. The method proposed can realize oblique photography of cracks, truly restore the original spatial shape and size of cracks, and improve the recognition accuracy of cracks. At the same time, this method only needs to perform binocular camera calibration once and perform stereo matching on a limited number of feature marker points based on their geometric features to obtain all the required calculation parameters. It has high computational efficiency, good matching effect, and the detection accuracy is not sensitive to illumination changes. This method solves the defect that the traditional 3D reconstruction technology based on binocular stereo vision is difficult to directly extract the crack boundary on the 3D point cloud of the structure surface, and is suitable for crack identification and parameter extraction of cracked surface of cylindrical members.

In order to investigate the effects of different factors on the seismic response of steel plate silos when considering the storage-wall interaction, this study analyses the structural acceleration response, displacement response, the structural energy consumption and the structural strain response of the steel plate silos under the full-filled storage and the half-filled storage state, by establishing three steel plate silos with different height-to-diameter ratios. Moreover, steel plate silos and reinforced concrete silos with the identical dimensions are modeled and exited by the same seismic waves to compare the differences in structural acceleration response, displacement response and energy consumption of the two silos in the half-filled and full-filled conditions. The results indicate that the peak absolute acceleration and peak relative displacement of the silo wall increase with the increasing height to diameter ratio and reach a maximum at the top of the silo. While the cumulative hysteresis energy dissipation and stain of the silo decrease with the increasing height to diameter ratio. Moreover, for different silo types, the response of the reinforced concrete silo is smaller than that of the steel plate silo.

The integrity analysis of the reactor plant under steam explosion was numerically studied for the potential safety problem of the cavity.Firstly, a refined reactor plant finite element model （FEM） was established, and verified comprehensively based on a slab explosion test.Secondly, the damage scope of the reactor plant under steam explosion was determined qualitatively based on the damage contours.Then, the damage mechanism of the reactor plant was revealed based on the displacement- and strain-time histories quantitatively.Next, the tightness performance of the nuclear containment was analyzed according to the tensile strain contours and the damage threshold.Finally, the influence of foundation strength on the blast resistance of the reactor plant was analyzed and recommendations for the design of the nuclear power plant （NPP） were proposed.It derives that： under steam explosion, the cavity wall endures complete damage and the main damage mode is tensile failure.Besides, concrete at the cavity bottom within the depth of 2 m enters plastic state with shear failure; under steam explosion, the NPP containment is safe and the tightness of the containment is good.

The amount of domestic construction spoil emission is significant, but the resource utilization rate is low. One feasible and high value-added way to utilize construction spoil is to produce nonsintered bricks. Firstly, the classification and main disposal methods of construction spoil are introduced, and the bottlenecks such as low-carbon dewatering of construction spoil raw materials and the difficulty of determining the process parameters are pointed out. Then, the common production process of nonsintered bricks along with the influence of molding, curing and other processes on the performance of nonsintered bricks are introduced. Next, the type of cementitious material and mixing, moisture content, admixtures and other factors on the mechanical performance of nonsintered bricks are further analyzed, and the resource reuse and low-carbon advantages of nonsintered bricks are summarized. The defects such as smooth surface not easy to combine with mortar, low shear strength, large dry shrinkage deformation, etc. are also reviewed. Finally, the future direction of research on nonsintered bricks from the perspective of green building is put forward.

The special-shaped building located on the steep slope is difficult to be realized with the conventional structure supported by foundations with different elevations or stilted building structure. Aiming at the special-shaped building under this terrain, a arch with inclined column structure was proposed and designed, which can not only better adapt to the architectural shape, but also solve the problem of foundation setting. Aiming at this structure, the influence of key parameters such as arch axis shape, arch rise-span ratio, arch tilted angle and column tilted angle on the mechanical performance and arch warping effect were analyzed in detail by using parametric analysis method. The results show that rise-span ratio has little influence on the bending moment of the arch and great influence on the axial force of the arch. Meanwhile, rise-span ratio also has great influence on the stability of the structure. Considering the architectural effect, structural force and structural stability, the rise-span ratio of the arch should be controlled between 0.2 and 0.3. When the rise-span ratio of arch is between 0.2 and 0.3, the influence of arch axis shape on structural stress can be ignored. With the increase of arch tilted angle, the section torque of arch increases rapidly, and the warping effect of arch foot and vault is obvious. When checking the strength of steel box section, the warping effect should be considered. The increase of column tilted angle reduces the internal force of arch, which is conducive to the stress of arch, and the stress of the structure can be improved by adjusting the tilted angle of the column.

This paper is based on the engineering background of super-tall towers in earthquake prone areas, comprehensively arranges the position, various deformation amplification devices, viscous damping parameters and other key contents to carry out the selection and analysis of viscous damping systems under wind and earthquake double excitation. Taking a 396 m super-tall tower as an example, the design of viscous damping systems under wind and earthquake double excitation is studied. Research has shown that viscous damping vibration reduction systems have a certain control effect on different modal responses, which can effectively improve the comfort, stiffness, and strength performance of structures under wind and earthquake conditions. Reasonable placement of dampers, deformation amplification devices, and parameter selection can achieve more efficient vibration reduction efficiency.

Precast concrete double skin shear wall （PCDSSW） is a new-type semi-prefabricated concrete structure element with sound structural integrity, high construction efficiency and low demand for formwork and labour. It consists of two precast concrete panels and one cast-in-place （CIP） layer between them. In order to investigate its mechanical behavior under lateral loads, finite element simulations were conducted using the software ABAQUS after the models had been proved reliable by comparison with the existing test data. The parameter analysis of vertical connections, design axial compression ratios and the concrete strength of CIP layers were carried out on 21 PCDSSW models. Analysis results indicated that the load-displacement curves of the walls with single-row dowel bar connection, double-row dowel bar connection and those without dowel bars in the middle walls were similar. The lateral load capacities of the walls with single-row dowel bar connections were 1.5%~7.5% higher than those with double-row dowel bar connections, and the capacities of the walls without dowel bars in middle walls were 5.7%~12.3% lower than those with double-row dowel bar connections. Secondly, the initial stiffness and load capacities of walls increased significantly with the axial ratios, while the load capacities and stiffness declined more rapidly under high axial ratio. In addition, low concrete strength of the CIP layers caused by insufficient vibration would lead to low load capacities, which should be avoided in construction.

Textile Reinforced Ultra High Ductile Cementitious Composites （TR-UHDCC） are advanced materials characterized by high strength, high ductility, crack resistance, and durability. Compared to traditional masonry reinforcement materials, TR-UHDCC exhibits superior performance. Based on existing experimental research results, this paper introduces the Hashin damage criterion to account for the damage behavior of the fiber grid, establishing a three-dimensional finite element model for TR-UHDCC. This model accurately simulates the stress-strain curve of TR-UHDCC and its corresponding characteristic points （cracking stress and strain, peak stress and strain, ultimate stress and strain）. Using this model, the effects of fiber grid distribution rates and the tensile strength of UHDCC on the characteristic points of TR-UHDCC were studied. Finally, a theoretical calculation model for the tensile load-bearing capacity of TR-UHDCC was developed based on the sectional force equilibrium relationship. The calculated values from this model align well with experimental and parametric analysis results, with an average error of only 3.63%.

The flat grid structure is widely used in large-span spatial steel structure system because of its good integrity, large spatial stiffness and flexible layout. The research focuses on the evaluation and reinforcement of a flat grid structure's bearing capacity, which is critical in cases of member damage due to factors such as material aging or construction issues. In this paper, SAP2000 finite element software is used to analyze the stress of a typical orthogonal square pyramid grid structure. According to the change law of mechanical index of grid structure after damage of different positions and numbers of members, a new calculation method of damage factor of grid structure is proposed. The calculation method has fewer parameters, simple calculation and high accuracy. The method of evaluating the bearing capacity of the grid structure and determining the repair measures according to the structural damage factor is proposed. For the grid structure that needs to be reinforced, this paper proposes a reinforcement method based on the importance of members.

Cement-based materials containing fiber are widely used in engineering structures. In order to study the bonding properties between steel fibers and cement matrix, this research investigated fiber pullout performance of steel fiber in cement mortar and high-strength grout. The bonding properties were evaluated by the indexes of maximum pullout load,energy dissipation and average bond strength. The test results show that the shape of the pullout load displacement curve in the high-strength grout is similar to that of the ordinary cement mortar. The mechanical anchoring effect exists between the deformed fibers and the matrix, and the maximum pullout load and energy dissipation are significantly increased compared with that of the straight fibers. Compared with the straight fiber, the average bond strength and energy disspation of the hooked fiber of ordinary cement mortar matrix are increased by 180.8% and 126.8%, respectively. In high-strength grout, the increase is 363.3% and 474.7% respectively. When the steel fiber has an inclination angle, the process of the pullout is usually accompanied by the spalling of the ordinary cement mortar matrix and the plastic deformation of the steel fiber. The increase of embedding depth will increase the pullout load and energy dissipation, but it may cause the fiber breakage for the waved fiber.

In order to determine the performance difference of the network tied-arch bridge with different deck structure, three types of bridge deck structure, namely concrete deck, orthotropic steel deck and steel-concrete composite deck, are used to design and study the 300 m span bridge. The finite element software ANSYS was used to establish three trial design scheme models, and compare their overall mechanical performance. At the same time, the amount of materials was counted, and the unit price of materials was introduced to compare their economic performance. The results show that the concrete deck has better economic performance for the 300 m network tied-arch bridge. Compared with orthotropic steel deck, concrete deck or steel-concrete composite deck can improve the structural stiffness to a certain extent. The distribution of internal force and stress along the longitudinal direction of the network tied-arch bridge is similar in different types of bridge deck, while the axial force of the structure and cable force at the bridge completion stage is significantly different.

The beam deflection control in current structural design standards is to ensure the serviceability function of the building, while the deflection limit value in the reliability assessment of existing structures and the deflection early warning value in structural health monitoring also have the purpose of controlling the safety of structural members. Aiming at the safety control of structural members, this paper established a theoretical relationship between the deflection to span ratio of beams and the maximum tensile strain of steel bars,and the calculation methods and recommended values of the mechanics characteristic coefficient, the section neutral axis height coefficient and the long-term deflection growth coefficient of the beams were studied. The relationship between beam deflection and maximum tensile strain of steel bars was verified by the experimental data, which showed that the accuracy of the comprehensive coefficient of the deflection to span ratio proposed in this paper meets the requirements of engineering calculation. The graded control method of maximum tensile strain of steel bars was established, and the graded limit of deflection to span ratio of beams was proposed accordingly. Compared with the deflection limits in current standards, the results showed that the deflection limits proposed in this paper are significantly different according to the specific characteristics of the beams. The range of the deflection limits is wider and more stringent than the current standards. The research findings in this paper can provide references for reliability assessment of existing structures and structural health monitoring.

To investigate the influence of milled-cut steel fiber （MSF） on the flexural behavior and toughness of plain concrete, four-point bending tests were conducted on C50 concrete matrixes with different volume fractions of steel fiber （0%,0.6%,1%,1.4%）. The flexural behavior,cracking mode,and failure mechanisms of milled-cut steel fiber reinforced concrete （MSFRC） was analyzed. The evaluation methods for flexural toughness of fiber-reinforced concrete in domestic and international standards were studied to assess their applicability. The results indicate that the maximum equivalent flexural strength of the MSFRC is 1.8 times than that of plain concrete. Upon surpassing the critical fiber volume fraction of 1%, the material displays multiple cracking characteristics,with strain hardening behavior observed at an enhanced fraction of 1.4%. The method specified in JG/T 472—2015 steel fiber reinforced concrete is applicable for characterizing the flexural toughness of milled-cut steel fiber reinforced concrete. The increase in fiber volume fraction enhances the flexural deformation capacity of concrete and improves the post-cracking flexural toughness within the small deflection range.

The frame-shear wall structure system was used in Photoelectric Information Building in Huazhong University of Science and Technology. A long-span structure with a span of 40 m was accomplished by using a multilayer vierendeel truss crossing 4 floors. The structure involved with structural irregularity problems such as the torsion irregularity, eccentric arrangement, slab with large opening, mutation of the bearing capacity, discontinuous structural elements, and regional skip-floor columns. A comparative study on the braced truss and multilayer vierendeel truss was conducted in this paper. The mechanical mechanism, internal forces of elements under vertical load and vertical seismic action, comfortability of the slab, design of the complex joint, the construction technique requirements, and behavior under rare earthquakes were analyzed. The measures were developed to reinforce the seismic capacity of the structure. The structure scheme of the multilayer vierendeel truss not only can meet the requirements of relevant codes and achieve the expected objective of seismic performance but also can meet the requirements of architectural function.

In the current research on seismic reduction design of school buildings using viscous fluid dampers, attention is often paid to the main structures such as teaching buildings and dormitory buildings, while neglecting the corridor space that plays an important role in the overall spatial organization of the campus. In order to study the application of viscous fluid damper in school corridor space, this paper takes the corridor space between teaching buildings in a primary school in Shanghai as an example for seismic reduction design. Firstly, conduct frequent earthquake analysis on the structure, and the results meet the requirements of the specifications. Secondly, conduct elastic time history analysis under fortification earthquakes and compare the seismic reduction effects when including the foundation layer or not, the arrangement of dampers in the inner or outer frame, the number of dampers changed, the floor of dampers changed, and determining the seismic reduction plan. Finally, conduct elastic-plastic time history analysis under rare earthquakes to calculate structural damage, energy dissipation, and drift ratio. The research results indicate that viscous fluid dampers can provide certain energy dissipation under earthquake action and are an effective seismic reduction method for school corridor spaces.

Based on the nacre toughing mechanisms, Engineered Cementitious Composites （ECC） were used as constructing mortar to improve the ductility and toughness of masonry structure. Five groups of masonry prisms with four types of bricks were carried out. The failure mode, stress-stain curve, ductility and toughness were comparably analyzed. The results demonstrated that the nacre-inspired masonry prisms had interface-slip and crack-deflection failure mode, which increased the ductility by a maximum of 10 times and the energy consumption capacity by a maximum of 77 times compared with conventional masonry. However, the brittle splitting failure occurred when ECC layer couldn’t provide sufficient confinement with the strength increease of brick layer. Based on the Digital Image Correlation （DIC） method,the collaborative work characteristics between brick and ECC lager was studied and the toughing mechanism was also discussed.

GFRP bar-UHPC members have excellent mechanical property and durability, and have wide application prospects. The bond performance between GFRP bars and UHPC is a key issue for the two materials to work together. Pull-out tests were carried out on 12 and 4 GFRP-bar-UHPC specimens under monotonic and low-cyclic loading respectively to study the effects of GFRP bars' surface treatment, bond length and cyclic loading on mechanical properties such as failure mode and bond strength. The results showed that all specimens exhibited pulling-out failure. The bond stress-slip curves of wire wrapping GFRP bars specimens exhibited more significant fluctuations up and down after the peak load. The bond strength between GFRP bars and UHPC decreases slightly with the increase of bond length. The bond strengths of wire wrapping GFRP bars specimens were higher than these of sand coated specimens. Meanwhile, the effect of low-cycle loading on the bonding properties of GFRP bars in UHPC was mild. Finally, based on a model proposed by Yoo, a bond strength prediction model considering surface features of the bar has been proposed.

To study the bearing capacity, deformation, and failure pattern of steel tube specimens filled with aluminium foam under quasi-static axial load, specimens with different lengths and thicknesses were tested, and the final failure pattern and axial force-displacement curve were obtained. On the premise of the reliability of the finite element numerical model, the influence of the section height of the steel tube filled with aluminium foam was analyzed. The research results show that the peak load and average load decrease with the increase of specimen length, whereas increase with the increasing thickness of the steel tube. Compared with the pure steel tube, the total energy growth rate of the steel tube specimen filled with aluminium foam with a cross-section height of 40 mm, 50 mm, 60 mm and 70 mm fluctuates within a certain range, and the steel tube specimen filled with aluminium foam with larger height-to-width ratio of section can resist deformation more effectively. The mechanical properties of the aluminium foam-filled steel tube specimen with a length of 150~250 mm and a rectangular section aspect ratio of 1.5 are best after buckling.

The current structural fire resistance research has relatively few studies for localized fire scenarios, and the test results are relatively scarce. Based on this, this paper attempts to build a realistic fire test platform, and adopts two fire source forms, jet fire and pool fire, to heat the H-shaped columns and record its thermal results. In terms of numerical simulation, unlike the iterative coupling method that applies the concept of adiabatic surface temperature, this paper realizes the two-way direct coupling of fluid-solid heat transfer by unifying the fire analysis with the thermal analysis using the CFD method. The distribution rules of the spatial velocity field and temperature field were explored in the fire analysis model, and the thermal characteristics of steel columns in different fire source environments were explored in the thermal model. The correctness of the direct coupling method was verified by comparing experimental data with simulation results. In addition, the theoretical and empirical formulas are applied to explore the distribution law of convective heat transfer coefficient of the steel column surface.

The bearing capacity of the existing wall after plugging reinforcement is studied. Considering the influence of stress lag effect, original stress level, opening rate and plugging material performance on the bearing capacity of the masonry wall after plugging, the corresponding calculation method is given. The results show that the use of the original masonry mortar and block materials can not meet the bearing capacity requirements of the wall ; improving the strength of masonry mortar and block materials can only meet the bearing capacity requirements of some walls ; the use of high ductile concrete to reinforce the wall is an effective means of repair, but there is also the possibility that it cannot meet the demand for bearing capacity.

Chinese mortise and tenon joints present significant historical and cultural value. Recently, BIM-based structural parametric design has been increasingly promoted and applied. Through the digital model, the entire life cycle of traditional structure will be recorded for their conservation. This paper summarizes the shape characteristics of typical mortise and tenon joints. Based on dimension feature, family templates of mortise and tenon joints were developed on the Revit platform, which improves modeling efficiency and accuracy.

On the basis of the parallel four-cable suspension bridge, four-cable suspension bridge with different sag solves the construction problem of limited height of the bridge tower, and lowers the main cable under the deck to maximize the sag of the main cable. As the critical load-bearing member of the suspension bridge, the axial force effect of the main cable under vehicle load deserves attention. Taking a four-cable super-span suspension bridge with different sag under construction in China as the research object, a structural finite element model is constructed by ANSYS, and the mechanical performance of four cables under vehicle load is analyzed. The results show that the distribution of dead load in cables with different sag is uniform. Under the action of symmetrical vehicle load, the lower cable will bear more vehicle load, with a distribution ratio of about 26.2% and the upper cable about 23.8%. Under the action of asymmetric load, the axial force of the lower cable on the action side can reach 34.6% of the total axial force, which is about 32% higher than that under the symmetrical load. The load distribution ratio of vehicles is independent of the change of traffic volume and the weight distribution.

Based on scaled physical model tests and three-dimensional finite element numerical simulation, the lateral bearing capacity and failure characteristics of grouted sleeve connected bridge piers for overpasses were studied, and their energy dissipation characteristics were explored. The cyclic loading test results of the grouting sleeve connected pier column indicate that there was no node failure before the pier column failure, and its mode was column bending failure. A refined finite element analysis model for grouted sleeve connected bridge piers was established, and an elastoplastic damage constitutive model for concrete was introduced to simulate the mechanical response and damage process of the bridge piers under reciprocating cyclic loads. Further analysis was conducted on the influence of axial compression ratio and prestressing level on the bearing capacity of bridge piers. The results showed that a high axial compression ratio is beneficial for improving the lateral bearing capacity of grouted sleeve connected bridge piers, but it will reduce their energy consumption and ductile deformation performance. Pre stressing can increase the lateral bearing capacity of bridge piers, slightly increasing their energy dissipation capacity, but reducing their ductile deformation capacity.

Offshore wind turbines （OWTs） are subjected to random wind and wave loads for a long time during use and are in a state of continuous vibration. The design of their dynamic characteristics is very important. A three-dimensional finite element model for frequency analysis of an actual monopile support structure for the offshore wind turbine under actual seabed foundation condition was established by using ABAQUS. Compared to commonly used soil spring model,the model can consider the actual three-dimensional soil conditions directly and no need to simplify the soil artificially, avoiding errors caused by simplification.. The correctness of the method is verified by comparing the reference value. Unlike traditional optimization for the cross-section of support structures, the article considers changing the pile types. Four types of special-shaped piles, including an extended pile, a pile with a cover plate, and two types of piles with wings, were designed on the basis of the ordinary monopile. The influence of pile types on the natural frequency of monopile support structures for offshore wind turbines and the performance of support structures with different pile types under scour were studied. The results indicate that taking into account the effect of frequency increase and the difficulty of piling, the use of piles with a cover plate on any soil seabed is the optimal way to increase the frequency of support structures for offshore wind turbines. Scouring can reduce the frequency of the support structures, and the impact on the pile with a cover plate is the greatest, which requires special attention in design.

The construction details and working principle of viscous damper is introduced. Taking a kindergarten located in an 8-degree seismic fortification area as an example, five natural earthquake waves and two artificial earthquake waves are selected by using the Midas Gen finite element analysis software to analyze the dynamic response of the structure under frequent earthquake and rare earthquake, and the energy consumption of the viscous damper under the three-level earthquakes is given. The results indicate that with the addition of viscous damper, the main structure has good seismic performance and can achieve the "three-level" of seismic fortification goals. Under rare earthquakes, the overall plasticity of the structure is relatively low, and the damage yield mechanism is reasonable. Viscous damper exhibit good energy dissipation characteristics under earthquake action, providing a lower additional damping ratio under rare earthquakes than under frequent earthquakes,and the dispersion of additional damping ratios for multiple sets of seismic waves is also lower. This work can provide reference for similar projects.

Aiming at the floor comfort of the long-span corridor structure, the comprehensive finite element model of the corridor is established, and the modal analysis of the structure is carried out by Ritz vector method. The vibration characteristics of the long-span corridor structure are studied and the vibration reduction design is analyzed. According to different crowd densities and walking frequencies, the vertical vibrations of the floor under four kinds of crowd loading are studied, and the vertical accelerations of the corridor structure before and after TMD installation are compared. The results indicate that the natural vibration frequency of the corridor is close to the walking frequency. Under the excitation of random pedestrian loads, the corridor exhibits resonance, leading to significant vibrations that can cause discomfort to occupants. Hence, it is necessary to implement measures to control and mitigate vibrations. By setting TMD in a reasonable position of the corridor, the overall vibration reduction rate is as high as 67.4%. The vibration of the floor can meet the human comfort requirements, which indicates that TMD plays an effective role in vibration regulation.

Multi-rope friction hoist is the only hub connecting the underground and the ground, and it is very important to ensure its safety. However, there is little research on the tension of multi-rope friction wire rope. Taking the wire rope in the hoisting system as the research object, the tension formula of wire rope in the existing literature is improved. The experimental value of wire rope tension is obtained through field measurement, and the improved formula is numerically simulated and compared with the experimental value and the formula before improvement. Finally, the dynamic response of the derrick structure is analyzed when the container is fully loaded. The results show that the maximum tension difference between the theoretical value and the experimental value calculated by the improved wire rope tension formula in this paper is 7.637 6%, and the maximum tension difference between the improved formula and the original formula is 0.070 3%, which is in good agreement. The amplitude of the loading point in the horizontal X and vertical Y directions at the moment of operation of the hoisting system increases rapidly to the peak value and then drops sharply, and then gradually tends to be flat.