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Copyright of Remote Sensing for Natural Resources is the property of Remote Sensing for Natural Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Affected by earthquake, the railway coordinate benchmarks within the epicenter range are prone to damage, and control points have varying degrees of displacement, resulting in varying degrees of damage to the track structure. To solve the problem of difficulty in quickly recovering from continuous damage to large-scale control points, taking the example of the engineering, a fast recovery method for the post earthquake railway precise engineering control network was proposed, with the stable CP0 as the constraint, compatibility analysis was carried out in conjunction with CP I control points, which dynamically updated the coordinates of different levels of control networks step by step. This maximized the utilization of the original control results, providing the position reference for emergency rescue after the earthquake. Based on the control results of different levels of precision measurement networks after reconstruction, combined with CP III remeasuring data, the lateral and longitudinal deformation values of the track were obtained, and the overall deformation characteristics of the railway line were quantitatively analyzed. Using methods such as three-dimensional scanning inside the tunnel to measure the clearance of the tunnel section, the segmented analysis of the multi-directional spatial deformation characteristics of the lining and other structures were completed, and the overall deformation trend of the track was matched. The degree of damage and deformation characteristics of the earthquake on the inside and outside of the Daliang tunnel were identified, providing the data benchmark for the usability evaluation of the track structure and engineering restoration. [ABSTRACT FROM AUTHOR]

Ancient buildings, the carrier of historical culture in China, contain high cultural value, historical value and scientific value. To prevent the damage of ancient building structures caused by strong earthquakes and industrial vibration sources, timber ancient buildings and brick-stone ancient buildings were firstly taken as the research objects, then the widely used seismic strengthening technology were systematically summarized based on the analysis of the earthquake damage characteristics of key nodes, components, and overall structure. Subsequently, in-depth discussions were conducted on the evaluation indexes and standards of ancient building vibration at home and abroad. Then a detailed introduction to the development history and precise prediction techniques of commonly used vibration response prediction methods of ancient buildings were showed. Moreover, based on multiple engineering examples, the vibration control technology of multiple defense lines has been condensed. Finally, the problems and the corresponding suggestion still existing in the research fields of seismic resistance and anti-vibration of ancient buildings were also pointed out based on summarizing research methods and research contents, which will provide a reference for the intensive researches on these fields, even the protection of ancient buildings. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: The Turkey-Syria earthquake occurred on February 6th, 2023, and caused heavy casualties and property losses. This paper used high-resolution night-time light images to assess the damage of the affected cities. Methods: A multivariate power function regression model was used for intercalibration between sustainable development goals satellite-1(SDGSAT-1) and Yangwang-1 night-time light images. And the disaster assessment was carried out in the cities of Adiyaman and Antakya-Defne in Turkey. Results: The results show that the power facilities of Adiyaman and Antakya-Defne were severely damaged in the earthquake. The light loss rate of more than half of the building area exceeded 80%, and the overall light loss rate of the building area exceeded 70%. Additionally, the light loss rate in the east of Adiyaman was higher than that in the west, and the light loss rate in the downtown area of Antakya-Defne was higher than that in the suburbs. Conclusions: The high-resolution night-time light images can effectively assess the impact caused by natural disasters, and the assessment results can also help local government departments guide emergency relief and reconstruction work after the earthquake. [ABSTRACT FROM AUTHOR]

Objectives: The Mw 7.8 earthquake occurred in Turkey on February 6th, 2023, which is a rare powerful earthquake in recent years. Building collapse detection is an important part of post-earthquake damage assessment and emergency rescue. Facing the emergency rescue and post-earthquake disaster assessment, this paper aims to comprehensively utilize the intelligent interpretation technology of satellite remote sensing, coupled with high-resolution optical daily and night-time light remote sensing images, and to efficiently assess the collapsed buildings in the extreme disaster areas with low time and labor costs. Methods: In this paper, we present a multi-level rapid localization scheme for disaster-affected regions. First, the proposed approach involves the utilization of low- and medium-resolution night-time light data to estimate the extent of extreme disaster areas. Subsequently, high-resolution optical remote sensing imagery is employed to extract the collapsed buildings. By training a semi-supervised deep learning network with a small number of manually collected samples, the scheme automatically identifies collapse areas, thereby facilitating the precise localization of collapsed buildings. A high-resolution architecture network, HRNet, is employed in this study. HRNet has the advantages in both sematic and spatial feature representation, and can capture the collapsed buildings with muti-scale characteristics. Results: Six cities along the border between the Arab Plate and the Eurasian Plate are severely affected, from Adelman to Kahraman Marrash, and then to Antakia. A total of 2 377 collapsed buildings are detected in the extreme disaster areas. Except for Nurdaji and Antakia cities, where the proportion of collapsed buildings exceeded 2%, the proportion of collapsed buildings in the other four cities is close to 1%. After manual verification, the recall rate of the intelligent interpretation plan is between 74% and 93%. Conclusions: The efficiency and effectiveness of this approach are demonstrated through its application in assessing the building collapse situation after the Mw 7.8 earthquake in Turkey. The proposed work can serve as a timely reference for macro decision-making in post-earthquake emergency rescue operations. [ABSTRACT FROM AUTHOR]

In order to explore the effects of composite sat erosion, freeze-thaw cycle and dry-wet cycle on the strong earthquake failure mode of existing pumped storage structures in high cold area, the concrete deterioration tests and structural damage analysis were carried out. According to the actual situation of the project, the high concentration composite sat solution was prepared, the test scheme was determined, and the deterioration law of concrete materials was obtained. Based on the test results, the influence of concrete deterioration on the displacement, stress and damage distribution of tower top is analyzed by numerical method. The results show that the mechanical properties of concrete decrease significantly due to three factors: composite salt erosion, freeze-thaw, dry and wet. Under the action of strong earthquake, the damage area of structures is mainly distributed at the junction of tower and backfill concrete. The deterioration of concrete changes the failure mode and damage distribution law of structures. The research is helpful to master the deterioration law of material properties of pumped storage structures in alpine region and provide reference for seismic design of engineering. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the drilling data of six typical sites in Longtoushan town and the test data of dynamic nonlinear characteristics of soil, the seismic response analysis models of the corresponding sites were established respectively. Under the action of ground motion acceleration in east-west direction obtained by Longtoushan town strong observation station (053LLT) during Ludian earthquake with half-amplitude, the equivalent linearization method of one-dimensional soil layer seismic response analysis was used to calculate the seismic response of each site and the effect of near-surface overburden soil layer on peak acceleration. Response spectrum of ground motion was also discussed, and the relationship between site effect and earthquake damage was analyzed.

Copyright of Transportation Science & Technolgy is the property of Transportation Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to guide the type selection of ballastless track on bridges in high-seismic earthquake regions, the type selection principle and requirements of ballastless track on bridges in seismic areas are proposed based on the engineering characteristics of ballastless track on bridges in earthquake regions. The technical characteristics, construction performance, durability, maintainability, economy and adaptability to earthquake of CRTS series ballastless track in China, the type selection scheme and engineering design countermeasures of ballastless track on bridges in earthquake regions are analyzed. The results show that inconsistent deformations are likely to occur in the joints between adjacent beams under earthquake, and once the continuous track slab is broken, it is harmful to the piers. The ballastless track on bridges in the earthquake regions should be given priority to adopt the unit ballastless track. Once the ballastless track on bridge is damaged under earthquake, it should have the ability to be quickly repaired. Considering the construction, durability, maintainability, economy and other aspects of the ballastless track, it is recommended to adopt the CRTS double-block ballastless track in high seismic earthquake regions. In order to ensure the safety of the ballastless track on bridges in earthquake regions, it is recommended to study the seismic design of the ballastless track, the earthquake disaster warning and monitoring system, and the seismic adaptive protection measures. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Track irregularity spectrum can represent and evaluate the macroscopic geometric state of a certain kind of track, which is an important index for the evaluation of track smoothness state and the judgment of track damages, and also one of the important input excitations. The construction of high-speed railway in China can hardly be located away from the earthquake area in time and space. If the earthquake damage of high-speed railway line is included into the track irregularity spectrum, the proposed track irregularity spectrum considering earthquake damage on high-speed railway bridge will be of great significance to comprehensively manage the track smoothness state of post-earthquake railway line and correctly evaluate the safety of train running after earthquake. Therefore, the calculation method of track irregularity spectrum for high-speed railway bridge considering earthquake damage is proposed, and the research progress of each part of the calculation method (including the integrated model of high-speed railway track-bridge system induced by earthquake, the evolution mechanism of earthquake-induced damage, the mapping mechanism of earthquake-induced damage and the track irregularity spectrum induced by earthquake ) is summarized. The research deficiencies and development trend of track irregularity spectrum on high-speed railway bridges considering seismic damage are pointed out. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advanced Engineering Science / Gongcheng Kexue Yu Jishu is the property of Advanced Engineering Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: Building damage information can provide an important basis for the decision making of rapid post-earthquake assessment. Traditional building damage detection techniques mainly focus on the roof surface, thus many damaged buildings with an intact roof surface but collapsed middle floors may be neglected. We propose a method of building façade damage detection based on deep learning and multiresolution segmentation algorithm. Methods: The method which integrates the instance segmentation and multiresolution segmentation algorithm is applied to detecting the post-earthquake building façade damage. The first thing is to collect the ground images of post-earthquake buildings in the field and perform the data augmentation. Secondly, we use the convolutional block attention module (CBAM) to improve Mask R-CNN. Then the dataset is input to the improved model for training, and finally a multiresolution segmentation algorithm is adopted to post-process the building façade damage detection results output by the CBAM-Improved Mask R-CNN.Results: The experimental results show: (1) Collecting ground images of buildings in the field and performing image augmentation can effectively guarantee the necessary training sample size of the instance segmentation model. (2) The Mask R-CNN improved by CBAM attention mechanism significantly improves the post-earthquake building facade damage detection capabilities, which realizes the precise extraction of damage information from complex building façade backgrounds. (3) In addition, using the multiresolution segmentation algorithm to post-process the building facade damage detection results can obviously solve the blurred boundary problems caused by the accumulation of convolutional layers. Conclusions: The proposed method can significantly improve the capability of post-earthquake building façade damage detection when compared to the traditional methods, which also raises the Mask R-CNN's accuracy, precision, recall and F2-score to a certain degree. It can be inferred that the proposed method has the strong potential to be applied to the post-earthquake building façade damage detection and therefore provides an important technical means for detecting the comprehensive and detailed building damage detection caused by earthquake. [ABSTRACT FROM AUTHOR]

Objective: Earthquake occurred frequently in China. More knowledge needs to be discovered to take timely emergency actions to mitigate earthquake damage. Thus the construction method of knowledge discovery model for earthquake emergency is one of the core research issues in earthquake emergency field. It is worth studying how to realize knowledge discovery for earthquake emergency from abundant and complicated data under less support of prior knowledge. Methods: We put forward a kind of text big data based knowledge discovery model for earthquake emergency. First, text data associated with earthquake emergency is collected, including both academic document data (CNKI(China national knowledge infrastructure) data) sets and social media data sets(Weibo data). Then CiteSpace tool and formal concept analysis method are utilized to extract the high-frequency keywords and their linkages, the linkages’ frequency between keywords as linkage strength, a complex network of earthquake emergency knowledge is established for community classification. After community dividing, several big communities can be divided from the former established complex network. Results: From big communities’ further analysis : (1) in seismic resistance design domain, the discovered knowledge has high coherence with expert knowledge; (2) in earthquake rescue domain, the discovered knowledge shows that China Earthquake Administration have responsibility to afford emergency information services as well as public opinion guiding; (3)in geological hazards domain, the discovered knowledge founds the vegetation restoration in geological disaster area should be paid more attention; (4) the knowledge discovered from academic document data and social media data can be complementary. Conclusions: The experiment result shows that the model can find relevant knowledge, especially those experts rarely concern. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An earthquake of Ms8.1 occurred on 25 April, 2015 in Nepal Himalaya, with a focal mechanism of low-angle thrust. This earthquake caused the collapse of a large number of buildings and landslides. According to the investigation,types of buildings investigated include reinforced concrete frame structures, brick concrete structure, brick-wood structures and rubble structures. Long axis direction of intensity circle is in the direction of NWW and the max intensity is Ⅸ and there appeared 2 macroscopic epicenters. About 589 landslides from the High-resolution Remote Sensing Image interpretation are distributed intensively in a strip, which is similar to topography, intensity and aftershock distribution and mainly distributed in the boundary area between Greater Himalaya and Lesser Himalaya nearly along the Main Central Thrust(MCT). Statistical data of slope gradient and aspect reveal that the areas where the gradient is from 30 to 50?nd aspect from 150 to 180?re most sensitive to landslide. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To address the shortcoming of ignoring the presence of enclosure walls in seismic analysis of ancient timber frame buildings, the influences of the structural detailing, mechanical property and plan layout of the walls and timber frames on the seismic performance of the overall structure were examined. Based on the statistical information on earthquake disasters, the damage characteristics of the wall and timber frame were summarized, and the corresponding overall damage degree to the ancient building were described. By means of dynamic property site test and finite element analysis methods, the influence of the walls to the fundamental period and earthquake performance of the ancient building was also studied. The research results show that the walls in the ancient building have an evident contribution to the overall seismic stiffness of the structure, the fundamental period of the model including the walls is close to the fundamental period obtained from the site test. However, the fundamental period of the model ignoring the wall is much greater than the site test result, rendering unsafe design. According to seismic evaluation requirement for ancient buildings and considering the brittle behavior of the brick wall, a three-stage seismic analysis method based on displacement control and taking account of various cracked working conditions of wall, is proposed for ancient timber frame buildings. [ABSTRACT FROM AUTHOR]

The characteristic ratio of seismic wall is an important parameter for seismic evaluation of multi-story masonry structures, which determines the results of earthquake disaster prevention and treatment measures. Firstly, in order to obtain a reasonable assessment of the characteristic ratio of seismic wall, some affecting factors and defects of the characteristic ratio of seismic wall of masonry buildings were analyzed. Secondly, an index of the ratio of constructional column area to wall area of masonry buildings was put forward. Meanwhile, the characteristic ratio of seismic wall of masonry buildings was studied at the earthquake field investigation point of view according to existing seismic evaluation theory and its judgment standards, and a new calculated model was put forward by taking into account the difference of the ratio of constructional column areas to wall areas and floor-slab type, which provides a new way to study the characteristic ratio of seismic wall. Finally, a comparison of characteristic ratio of seismic wall of masonry buildings between the new model and the existing seismic appraisal standard was studied with some examples. Results show that, the characteristic ratio is close when floor slab is precast and the number of constructional column is low. With the same seismic capacity, the increase of the number of constructional column in brick walls will reduce the value of characteristic ratio of seismic wall of masonry buildings. [ABSTRACT FROM AUTHOR]

A strengthening method based on engineered cementitious composite (ECC) was proposed for an earthquake-damaged reinforced concrete (RC) frame model. Vibration and low-cyclic reversed loading tests were conducted. Test results show that the basic frequency of earthquake-damaged RC frame model retrofitted by ECC is decreased by 6.8% after loading test which indicates only a minor damage in the strengthened frame model, while the displacement angle is 1/48 at the yield load, 1/25 at the peak load and more than 1/19 at the ultimate load. The capacity of the retrofitted RC frame is enhanced by 9.6% compared to the original undamaged frame, which shows the seismic bearing capacity of damaged RC frame can be recovered or even exceeded that of the original frame because of the strengthening by ECC. The energy dissipation capacity of retrofitted frame can be restored to the level of original undamaged frame from the view of equivalent damping coefficient. In addition, the enhancement of stiffness of damaged RC frame was quite little by the strengthening of ECC, and stiffness of retrofitted frame was only 36.0% of the original undamaged frame, but the stiffness degradation was much slower than that of original undamaged frame. The results of strain analysis indicate that the mechanical behavior and failure mode of plastic hinges can be significantly improved by replacing concrete with ECC. [ABSTRACT FROM AUTHOR]

Both experiment design and numerical model updating for high-rise structure with ring shaped tuned liquid damper (TLD) are investigated in this paper. According to a real high-rise structure, a scaled model structure for the dynamic experiment was designed, using the similitude law of the structural mode lacking artificial mass. Both the lumped mass model and finite element model of the scaled structure were established, and its dynamic characteristics were compared with the real structure, so as to validate the rationality of the scaled model. The frequency and damping ratio of the scaled model were obtained from free damping experiment. Also, the applicability of wireless sensor in the dynamic test of high-rise structures was discussed using the experimental data. A model updating method using genetic algorithm was proposed and programmed, then a numerical simulation was conducted using structural stiffness and base rotational stiffness as variables to study both static and dynamic characteristics. The results show that the designed model can meet the similitude and reflect the dynamic behavior of the real structure in some degree. And the proposed method is a numerical model updating method with high efficiency, as it can converge within only 50 iterations. The work may offer both experimental and numerical models for the further investigations of vibration control experiment of the high-rise steel chimney with ring shaped TLD. [ABSTRACT FROM AUTHOR]

Based on a practical engineering project, a shaking table test of a 1/15 scaled model was accomplished to obtain the failure mode of the trussed arch structure. The similitude relationship, design of the scaled structural model, instrumentation and test procedure were described. The experimental results of natural frequency, damping ratio, acceleration response, displacement response and member strain under the action of artificial waves were presented and analyzed in terms of the change rule of vibration characteristics and the failure mode of structure. The results show that, with the increase of peak ground acceleration, the natural frequency and equivalent stiffness of model will decrease obviously while the damping ratio increase. The acceleration and displacement responses are enlarged gradually as the seismic waves propagated to the top of the model. When the peak ground acceleration reaches 0.8 g, large numbers of main truss diagonals are buckled and the structural stiffness is declined rapidly. At the end of experiment, the structural stiffness is decreased by 50% and the main trusses has in-plane anti-symmetric deformation. [ABSTRACT FROM AUTHOR]

In this paper, by investigating the influence upon the structural response of the points of force application for the known load pattern, the concept of load-correlating center of rigidity of building structure is developed, which depends on both the structural stiffness property and the load distribution. To take the structural responses of deformation and internal force into consideration comprehensively, the total strain energy of the structure is selected as the measurement of the structural torsional response intensity. By minimizing the response strain energy of the building structure, the explicit calculation formulas for the load-correlating rigidity center is derived. Through computation and comparison for several typical example structures, it is found that the structural torsional deformation decreases observably if the points of force application for the vertical distributed load are moved from its traditional rigidity centers to the load-correlating ones, which shows that the eccentricities between the centers of mass and the load- correlating centers of rigidity can be taken as a set of valid parameters to measure the performance of the torsional resistance of the structural seismic design scheme, and then, to provide guidance for the seismic design of building structure. [ABSTRACT FROM AUTHOR]

Elasto-plastic analysis method is an important means in performance-based seismic design. Since there are many factors that will affect the calculation results, it is essential to give a reasonable judgment on the analysis results. The quantitative relationship between high-rise building structure's stiffness degradation and additional damping ratio caused by elasto-plastic energy dissipation was discussed from the theoretical viewpoint. On this basis, the formula of changes in internal force response and displacement response with overall stiffness degradation was derived, and impact of some relevant parameters on the proposed formula was also discussed, such as vibration period, initial damping ratio, characteristic period of ground motion, etc. In addition, some special response problems, such as inconsistent internal force and displacement trends, and the greater magnitude of base sear response from elasto-plastic analysis than that from elastic result, were also focused on and analyzed reasonably. At last, the elastic and elasto-plastic time- history analysis were conducted for an actual project, and the total base sear force and displacement response variation ratio were obtained. At the same time the coefficient was calculated by the proposed formula in this paper and the results show that both results are basically consistent. The research conclusions can provide theoretical reference to performance-based seismic design and elasto-plastic analysis results' evaluation. [ABSTRACT FROM AUTHOR]

Based on the force transfer path analysis, the composite shear wall plays a very important role in terms of sustaining and transferring horizontal and vertical loads. From component to system, a relatively comprehensive review of the studies at home and abroad on the seismic performances of wall studs, fasteners and the composite shear wall is presented. A statistical analysis was implemented mainly based on the data of typical shear resistance experimental results at home and abroad of cold-formed thin-walled steel composite shear walls, indicating how the sheathing boards, fasteners, steel frame, aspect ratio, opening size and loading regime make influence on the shear performance of shear walls. Some experimental results were compared with the design guidance values of Chinese code finding that the design guidance values after linear interpolation make a conservative prediction of shear resistance with large spacing fasteners. The calculation of reliability index was made with the partial safety factor for resistance given in Chinese code, showing that the design guidance values of Chinese code can't satisfy the objective reliability index 3.2. The recalculated reliability index with partial safety factor for resistance adjusted according to a reference's recommendation are in good agreement with objective reliability index and there will be a lot of work remaining to do for a more appropriate value of partial safety factor for resistance. Some suggestions on the seismic performance research field of this kind of structures system are proposed. [ABSTRACT FROM AUTHOR]

Shaking table model test is one of the important methods to study the mechanism of earthquake damage and evaluate the anti-seismic capacity of the overall structure, how to deal with the similarity relation between test model and prototype and how to deduce the response of prototype from the response of model correctly are the key issues. A model of twelve-storey high--rise building frame structure was designed and tested based on the shaking table test, and dynamical analysis under seismic action for prototype and model was done by large nonlinear finite element analysis software MSC. Marc. The seismic response of prototype structure was deduced from model response according to the dynamic similarity relation, and compared with the calculated value of prototype structure. The accuracy of similarity relationship between model and prototype structure was verified by comparing the natural vibration properties, acceleration, displacement and shear, vibration table model test could reflect truly the seismic response of prototype structure, thus the earthquake resistant behavior of prototype structure could be evaluated according to the test results of model. [ABSTRACT FROM AUTHOR]

Considering the material nonlinearity of dam concrete and foundation rock and radiation damping of infinite foundation, a realistic seismic response analysis for Koyna gravity dam is carried out, which gives a reasonable explanation for actual earthquake damage. The same response was analyzed by using conventional methods. It can be seen that the linear elastic model for dam concrete can't truthfully reflect the possible crack distributions. It can only predict the crack location to some extent. Compared with the simulated results by using the conventional methods, the cracking scope is a little larger based on the pre-set crack method, in which initial tensile and shear strength of the material are taken into account. Therefore, the pre-set crack method is reasonable and feasible because the actual project requires some security reserves. [ABSTRACT FROM AUTHOR]

The seismic resistance capability of RC frame structure was studied with incremental dynamic analysis (IDA) method in terms of the 4 performance objectives (frequent seismic design of class C, frequent seismic design of class B, non-yielding design under moderate earthquake and elastic design under moderate earthquake ). Taking frequent seismic design of class C as basis, results of IDA analysis indicate that both seismic measures and seismic design force are very important influencing factors on seismic performance. The RC frame structures that are designed strictly conforming to the Chinese seismic design code have enough safety margins and the performance level of 'noncollapse under rare earthquake' can be reached. When the fortification intensity is 6, improving seismic measures for frequent seismic design of class C or increasing seismic design force for moderate seismic design has little influence on seismic performance. When the fortification intensity is 7, the collapse resistance capability of RC structures designed under moderate seismic force can be improved obviously. When the fortification intensity is 8, both improving seismic measures and increasing seismic design force can significantly raise the seismic resistance capability of RC frame structure. Especially, designed under moderate earthquake, the RC frame structure can withstand PGA of 1 000 gal without collapse. [ABSTRACT FROM AUTHOR]

Seismic design should quantitatively evaluate and control the earthquake collapse risk that building structures are likely to encounter during the design service life, which needs taking both the structural collapse resistant capacity and the earthquake demand into consideration. Firstly, this paper introduced IDA-based collapse fragility analysis and seismic hazard analysis, which evaluated the structural collapse resisting capacity and the earthquake demand in terms of probability, respectively. Furthermore, the structural collapse probability was proposed for measuring the earthquake collapse risk and its calculation method was provided. Finally, the collapse probabilities of RC frame structure for three seven-fortification areas with different seismic hazards were calculated as an example. The result shows the inadequacy of evaluating earthquake collapse risk only based on seismic fortification. The uniform-risk-targeted seismic design was proposed for collapse safety. [ABSTRACT FROM AUTHOR]