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Masonry structures are highly vulnerable to collapse when subjected to blast shock waves. However, existing research primarily concentrates on the response of masonry walls under blast loading, with limited investigation into the response of three-dimensional full-size masonry structures. Therefore, this paper investigates the effects of blast distance and blast equivalent on masonry structure damage using the continuum-discontinuum element method (CDEM). The integration of the HJC element constitutive model, fracture energy contact surface constitutive model, and shock wave fast imposition algorithm into CDEM enables efficient calculation of the damage process of masonry structures under the influence of shock waves. Initially, the blasting process of a masonry wall was numerically simulated, yielding results consistent with experimental findings. Subsequently, the entire damage process of a 3D full-size masonry structure under blast loading was simulated. The findings indicate that at short distances from the blast, the wall may detach directly from the concrete frame due to shock wave overpressure reaching the material's ultimate compressive strength, leading to structural instability. As the distance increases beyond a critical value, the shock wave's effect weakens, and wall damage transitions gradually to bending damage. [ABSTRACT FROM AUTHOR]

Perforated clay brick masonry is a popular and widely used construction, offering both structural and aesthetic benefits. The structural behavior of perforated clay brick masonry walls is a significant topic in the field of civil engineering. However, understanding the compressive and tensile strength of these walls are influenced by various factors such as the quality of mortar joints, the distribution of mortar, and the presence of reinforcement. The purpose of this study is to investigate the compressive behavior of four perforated clay brick masonry walls, using cement-sand mortar, with two different systems under in-plane compression load. The first masonry system is unreinforced with filling joints, and the other system is reinforced by steel bars embedded in the mortar as a low reinforcement ratio. The study provided valuable arguments about how mortar distribution affects wall performance, which is significantly impacted by poor quality of head joints and the fully or partially distributed mortar in the masonry joints. Also, the role of low reinforcement ratio within the construction industry has important effect. The mentioned parameters are investigated through practical case studies demonstrating their effects in the context of ductility and ultimate load capacity. It was found that the compressive strength of the unreinforced masonry system is highly increased to the distribution of the mortar by 35 % and 133% for filling all holes in brick units and the head joints, respectively, due to increasing the bonding between brick units in the masonry wall specimen. In the reinforced masonry system, the utilization of a low reinforcement ratio is increased the ultimate load capacity by 60% and decreased the ultimate displacement by 54%., but it is no longer provided significant changes to the ductility.

Recently, deteriorated masonry structures aged over 30 years have shown serious structural problems. Simple and rapid maintenance plans are urgently needed for aging masonry structures. Polyurea (PU) is an effective retrofitting material for aging structures due to its easy spray application. This process saves time, reduces costs, and allows the structure to remain in use during retrofitting. However, a general PU is not suitable for retrofitting aged masonry and concrete structures due to its low stiffness. In this study, stiff-type polyurea (STPU) was selected as the reinforcement material for masonry structures. It was developed by modifying the chemical mix of general PU to improve stiffness. To evaluate the strengthening effect of STPU on masonry members under static loading, tests were conducted. The flexural load capacity of masonry beams with STPU-sprayed surfaces was assessed. Three different types of STPU applications were used to select the most efficient strengthening method. Reinforcing masonry structures with STPU allows brittle failure modes to achieve ductile behavior. This improves their structural performance under lateral stresses. The experimental data were used to calibrate FEM models for simulation. These models can be used for future parametric studies and masonry structural design. [ABSTRACT FROM AUTHOR]

In order to explore the distribution law of the peak value of floor vibration velocity under the influence of blasting vibration, the blasting vibration data through on-site vibration monitoring of 7-story masonry structure was collected taking the tunnel blasting project of Gui-Xi section of Qingdao Metro Line 1 as the background. According to the actual working conditions, four numerical models with different blast center distances were established to analyze the vibration response characteristics of buildings. The results show that the combined vibration velocity of the top floor of the masonry structure shows a relative amplification phenomenon with different blast center distances of 2 m, 10 m and 35 m respectively, and the relative amplification coefficients are 2.02, 1.80 and 1.67 respectively. With the decrease of the blast center distance, the relative amplification coefficient of the masonry structure shows an increasing trend. When the blasting center distance is 70 m, the vibration velocity of the masonry structure decreases with the increase of the floor, showing an absolute decrease. The research findings herein have certain guiding significance for judging whether the building exceeds the safe allowable vibration velocity and optimizing the blasting parameters of urban tunnel excavation in practical engineering. [ABSTRACT FROM AUTHOR]

In the last decade, the documentation of historical buildings has made tremendous progress in generalising the use of high-precision laser scanning and drone photogrammetry. Yet the potential of digital surveying is not fully exploited due to difficulties in manually analysing large amounts of collected data. Machine learning offers immense potential as a game-changer in building archaeology, especially for the documentation of structures composed of millions of units. This paper presents the first segmentation of large-scale surveys of historic masonry using machine learning, using the thirteenth-century Basilica of St Anthony (Padua, Italy) as a case study. Based on a drone survey of the north façade of the building (110 × 70 m), a state-of-the-art non-learning segmentation approach is described and its limitations for historical structures are illustrated. Then, a new workflow based on convolutional neural networks (CNN) is presented. The result is a precise mapping of about 300,000 individual bricks showing a large variety of formats and bonds. The automatic surveys are analysed using visual programming language (VPL), enabling a rapid and feature-based identification of building phases and repair interventions. The outcome demonstrates the validity of machine learning for the analysis of historical structures and its potential in the field of heritage. [ABSTRACT FROM AUTHOR]

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Copyright of Kufa Journal of Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Frequent seismic events have demonstrated that building collapse is primarily caused by the loss of load-bearing capacity in vertical structural members. In response to this risk, various national design codes have been established. This study conducted field investigations at an earthquake site in Luding County, Sichuan Province, which was struck at a magnitude of 6.8 on 5 September 2022. In this case, the lower x-direction load-bearing wall of the Tianyi Hotel suffered severe shear damage, and the building was on the verge of collapse. However, no obvious damage was seen in the elementary school dormitory. Numerical simulation analysis revealed that during the earthquake, the buildings primarily experienced y-direction displacement in the x-direction, with significant differences in the stress state among different axes. In the model of Tianyi Hotel, the x-direction load-bearing walls suffered shear damage, while the frame columns were still in the elastic stage. At this point, the shear force of the walls was 6–9 times that of the frame columns. Comparing the damage characteristics of the two buildings during the earthquake, it was found that different structural forms lead to different internal force distributions. This phenomenon is further interpreted through the principle of "deformation saturation", with core structural components being modeled and tested using quasi-static experiments. The results indicated substantial differences in material properties among different structural forms, including variations in lateral stiffness, ultimate load-bearing capacity, and maximum displacement. Moreover, at the same floor level, components with smaller ultimate displacements are decisive of the overall structural stability. To ensure seismic resilience and stability, it is essential to consider not only the load-bearing capacity but also the rational arrangement and cooperative interactions between different components to achieve a balanced distribution of overall stiffness. This approach significantly enhances the building's resistance to collapse. [ABSTRACT FROM AUTHOR]

Decisions related to life safety risk management under natural disasters such as earthquakes may have a significant impact on social and public safety. Therefore, the risk of engineering structure should be limited to a reasonable and acceptable level, so as to achieve the comprehensive best in terms of economic investment, use benefit and life safety protection. To answer the question “How safe is safe enough?”, the life quality index (LQI) is firstly determined according to basic national conditions and economic level of China in 2018, and establishes the LQI-based risk acceptance criteria. Secondly, the reliability of new masonry structures and strengthened masonry structures are analyzed, and the failure probability of masonry structures under earthquakes is calculated by Monte Carlo method. Finally, the seismic risk control decision-making method of masonry structures is established, and two examples are given to illustrate the optimal design scheme of new masonry structures and the optimal strengthened strategy of existing masonry structures. The results show that the requirements of the proposed method for the reliability index of the new masonry structure are basically consistent with the provisions of codes, and the acceptable failure probability of masonry structures subjected to earthquake is between 0.001 and 0.010. [ABSTRACT FROM AUTHOR]

This paper presents an assessment study of traffic-induced ground vibrations and their effects on masonry-type historic structures in Ayutthaya Historical Park, a UNESCO World Heritage Site in Thailand. The first objective is to propose a practical prediction of the attenuation rate of vibration for risk management of the monuments located along roadsides in the city. The attenuation of vibration waves traveling from traffic sources and the intensity of ground vibrations were determined by in situ vibration measurement. The results from the investigations in the Ayutthaya area were compared with those obtained from other sites having different characteristics of subsoil classified by the average shear wave velocity (Vs). It was found that the attenuation rates at a long distance from the source tend to be dependent on soil property in terms of Vs of subsoils. The attenuation curves derived from the regression analysis are proposed for risk management from the vibration of the heritage site. The second objective is to assess the effects of traffic vibrations on historic structures. The highest amplitude observed in Ayutthaya was within the recommended vibration criteria for historic buildings. In addition, finite element analysis of a 3D stupa model revealed that the stresses resulting from the ground vibration records induced by traffic was lower than the strength of ancient brick and mortar. [ABSTRACT FROM AUTHOR]

Detecting cracks can be challenging, especially on rough surfaces such as masonry. This research paper focuses on the detection of surface cracks on masonry surfaces using deep-learning techniques. This study compared the performance of various networks trained using deep-learning techniques for semantic segmentation of cracks on masonry surfaces. For the semantic segmentation of cracks, the segmentation models U-Net, feature pyramid network (FPN), DeepLabV3+, and PSPNet were integrated with several convolutional neural networks (CNNs) acting as the network's backbone. Two loss functions, binary cross entropy and binary focal loss, were used in the study. Comparisons among networks using different metrics were performed to find the most promising approaches. Over the training and validation masonry data sets, a total of 23 networks were examined. The results of this study show that three networks can also accurately detect finer surface cracks on masonry surfaces. Based on performance metrics [dice coefficient, intersection over union (IoU), and F1 score], the three best networks were FPN(#2a) (86.9%, 74.9%, 59.3%), FPN(#2c) (85.6%, 75.4%, 56.3%), DeepLabV3+(#1a) (83.1%, 72.0%, 54.4%), respectively. Trained networks have demonstrated proficient performance on existing masonry culverts. This study can significantly aid the detection of cracks in the masonry substructure of old railway bridges. [ABSTRACT FROM AUTHOR]

Arches and vaults are typical elements of ancient buildings. They are formed by voussoirs that resist the pressure they receive and transmit them through compression forces. The transmission of these forces justifies their curved shape. For this reason, arches and vaults are omnipresent elements in ancient constructions, all of them masonry structures. However, when visitors enter the Basilica of the Monastery of El Escorial, they find a narthex with a flat or planar vault. This vault is located under the floor of the choir loft. Its geometric characteristics and its shape, with no curvature, make it an architectural anomaly and a brilliant solution within masonry structures. Therefore, this article tries to analyse the construction process and structural behaviour of this vault, to understand its operation and how it remains standing five hundred years after its construction. [ABSTRACT FROM AUTHOR]

A novel less-destructive field impression method that overcomes the uncertainties in stability assessments of rock joints in historical monuments, due to material sampling or existing destructive test limitations, has been developed. A thermoplastic resin with low fluidity and a short curing time is used to obtain the surface morphology of rock joints owing to its less destructive nature and wide applicability to the walls and ceilings of historical monuments. However, the insufficient filling of this thermoplastic resin can decrease the geometric accuracy of the impressions. Thus, the geometric accuracy of resin impressions and mortar replicas has been examined through laboratory experiments, and the results have been compared with those obtained using existing silicone-based methods, based on the statistical indicators associated with mechanical replicability. The indicator values of the method developed in this study were comparable to those of the replicas in previous studies that have sufficient geometric accuracy to satisfy mechanical replicability requirements. Furthermore, although roughness-coefficient-based methods underestimate the shear strength because of the insufficient filling of thermoplastic resins, they provide an acceptable safety margin in stability assessments of rock joints. The proposed method is suitable for conducting accurate stability assessments of historical monuments and ensuring their conservation.

Frequent seismic events have demonstrated that building collapse is primarily caused by the loss of load-bearing capacity in vertical structural members. In response to this risk, various national design codes have been established. This study conducted field investigations at an earthquake site in Luding County, Sichuan Province, which was struck at a magnitude of 6.8 on 5 September 2022. In this case, the lower x-direction load-bearing wall of the Tianyi Hotel suffered severe shear damage, and the building was on the verge of collapse. However, no obvious damage was seen in the elementary school dormitory. Numerical simulation analysis revealed that during the earthquake, the buildings primarily experienced y-direction displacement in the x-direction, with significant differences in the stress state among different axes. In the model of Tianyi Hotel, the x-direction load-bearing walls suffered shear damage, while the frame columns were still in the elastic stage. At this point, the shear force of the walls was 6–9 times that of the frame columns. Comparing the damage characteristics of the two buildings during the earthquake, it was found that different structural forms lead to different internal force distributions. This phenomenon is further interpreted through the principle of “deformation saturation”, with core structural components being modeled and tested using quasi-static experiments. The results indicated substantial differences in material properties among different structural forms, including variations in lateral stiffness, ultimate load-bearing capacity, and maximum displacement. Moreover, at the same floor level, components with smaller ultimate displacements are decisive of the overall structural stability. To ensure seismic resilience and stability, it is essential to consider not only the load-bearing capacity but also the rational arrangement and cooperative interactions between different components to achieve a balanced distribution of overall stiffness. This approach significantly enhances the building’s resistance to collapse.

This study presents the most recent development of a nationwide earthquake risk model for non-engineered masonry buildings in Malawi. Due to its location within the East African Rift, Malawi experienced several moderate earthquakes that caused seismic damage and loss. Recently, a new probabilistic seismic hazard model has been developed by considering fault-based seismic sources, in addition to conventional areal sources. The most recent 2018 national census data provide accurate exposure information for Malawian people and their assets at detailed spatial resolutions. To develop seismic fragility functions that are applicable to Malawian housing stocks, building surveys and experimental tests of local construction materials have been conducted. By integrating these new developments of seismic hazard, exposure, and vulnerability modules, a quantitative seismic building collapse risk model for Malawi is developed on a national scale. For the rapid computation of seismic risk curves at individual locations, an efficient statistical approach for approximating the upper tail distribution of a seismic hazard curve is implemented. Using this technique, a seismic risk curve for a single location can be obtained in a few seconds, thereby, this can be easily expanded to the whole country with reasonable computational times. The results from this new quantitative assessment tool for seismic impact will provide a sound basis for risk-based disaster mitigation policies in Malawi. [ABSTRACT FROM AUTHOR]

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. 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 Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management 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.)

Seismic loads pose a great risk to existing masonry buildings. Modern seismic control methods that are being increasingly used today, rather than various traditional strengthening methods, appear in the retrofit of existing masonry structures. The use of seismic control in existing masonry buildings increases the functionality of the building and obviates the need for additional structural requirements. Particularly, seismic control methods are superior because they contain the least possible interventions to architectural details. On the other hand, these methods are a unique option in sensitive structures such as historical masonry structures. In this research, base isolation systems, energy-damping systems, and hybrid systems as well as architectural application details of seismic control methods in masonry structures are discussed in the context of architectural details. [ABSTRACT FROM AUTHOR]

Slow-moving landslides cause significant economic losses associated with damage to facilities and interruption of human activity in mountainous regions and along river valleys. Physical vulnerability of structures exposed to slow-moving landslides is a required input for informed risk mitigation decision-making. However, the quantification of this vulnerability is still a major challenge. Few studies have been completed on this topic due to the limited historical data of the building damage associated with the comprehensive descriptions of the landslide mechanism. This research presents an experimental approach to investigating the mechanism of damage development and evolution on masonry buildings exposed to ground tension cracks associated with slow-moving landslides. A one-tenth scale model of a masonry building was designed and tested on the newly developed test table. The details of the testing setup are presented in this paper. The scaled model was constructed using sintered clay brick masonry and an unreinforced concrete foundation. An artificial tension crack was opened under the scaled model through the application of loading steps, in the direction parallel to the model foundation. The internal strains and associated forces developed on the scale model walls and foundation were measured by strain gauges. It was observed that the damage ranged from cracking to partial out-of-plane failure of the walls and the foundation. The damage level increased with the propagation of the tension crack on the test table. The final observation results were compared and validated against the field observations of damaged buildings on slow-moving landslides in TGR area in China. The experimental loading device simulated building damage caused by ground horizontal displacements and can bridge the gap in understanding the effects of slow-moving landslides on structures. It provided a new way to analyze the vulnerability of masonry structure under horizontal movement patterns of slow-moving landslides. [ABSTRACT FROM AUTHOR]

This study presents the most recent development of a nationwide earthquake risk model for non-engineered masonry buildings in Malawi. Due to its location within the East African Rift, Malawi experienced several moderate earthquakes that caused seismic damage and loss. Recently, a new probabilistic seismic hazard model has been developed by considering fault-based seismic sources, in addition to conventional areal sources. The most recent 2018 national census data provide accurate exposure information for Malawian people and their assets at detailed spatial resolutions. To develop seismic fragility functions that are applicable to Malawian housing stocks, building surveys and experimental tests of local construction materials have been conducted. By integrating these new developments of seismic hazard, exposure, and vulnerability modules, a quantitative seismic building collapse risk model for Malawi is developed on a national scale. For the rapid computation of seismic risk curves at individual locations, an efficient statistical approach for approximating the upper tail distribution of a seismic hazard curve is implemented. Using this technique, a seismic risk curve for a single location can be obtained in a few seconds, thereby, this can be easily expanded to the whole country with reasonable computational times. The results from this new quantitative assessment tool for seismic impact will provide a sound basis for risk-based disaster mitigation policies in Malawi.

The collection of relevant information about the vulnerability of infrastructure damaged by landslides is not an easy task due to the existence of several compounding factors and uncertainties. This makes it difficult to quantitatively estimate their vulnerability to slow-moving landslides. This paper presents a new vulnerability assessment model for masonry buildings on slow-moving landslides based on physical models and field observations. A masonry building model is made of brick and concrete at a scale of 1:10 to physically simulate the damage in structures caused by ground tension cracks commonly developed on slow-moving landslides. The tension crack opening process is simulated through a load-controlled table with an aperture on which the building model is constructed. The strain on the wall and its foundation were measured, and the damage of the model (crack formation and evolution for each loading step) was collected, described, and analyzed. These data were used to develop failure criteria for masonry buildings in rural areas in China in terms of a quantitative vulnerability curve. The quantitative model of vulnerability for masonry structures was established based on fuzzy mathematics and the Weibull function applied on the test data and observations. The vulnerability curve is verified with field cases of masonry buildings damaged by ground tension cracks associated with slow-moving landslides in the Three Gorges Reservoir area. The results support further testing and use of vulnerability curve proposed. [ABSTRACT FROM AUTHOR]

In the current age of overwhelming globalisation, the preservation of cultural heritage has acquired a primary role as a landmark of culture and diversity between peoples. Among the main characters of this field there are monumental buildings, often appearing as large structures characterised by a sequence of poorly known construction phases determining high structural complexity. Their evolution throughout centuries, strongly influencing their structural behaviour, is frequently almost unknown and hard to comprehend only by reading historical sources. The present paper deals with the application of a methodology to reach a proper and in-depth knowledge of the state of the art of a monumental building, necessary for the possible structural disaggregation of the compound, simplifying the structural analysis and the following preservation. In particular, a focus was devoted to the integrated approach to be adopted to reconstruct the morphological evolution. The Certosa di Calci monumental building is introduced and described as a reference case study. [ABSTRACT FROM AUTHOR]

Autoclaved aerated concrete is successfully produced as masonry units to construct single and multi‐family houses. Residential buildings are often erected as load‐bearing structures. Although designers are used to verifying the masonry structure for mainly vertical loads, some elements must act as a stiffening of the building. Horizontal loads of the building can be caused not only by wind pressure and suction but also by uneven subsidence of the ground or mining influences. The role of the stiffening walls is to ensure the geometric invariability of the building and the safe transfer of horizontal loads to the foundations. The Silesian University of Technology conducts extensive research on stiffening walls on full‐scale models of single‐storey buildings. Experimental analyzes enable the description of the propagation and morphology of cracks. Designation of the behavior phases of the stiffening walls is the basis for developing the calculation methodology for stiffening elements. [ABSTRACT FROM AUTHOR]

Considering the structural types and construction techniques used in common residential buildings in Xinjiang, the paper proposes a novel masonry structure, i.e., desert-sand AAC blocks constrained by a precast integral construction column. In order to study the seismic performance of the structure, five wall specimens with different constraints are designed and fabricated and further compared and analyzed in terms of failure mode, hysteretic performance, energy dissipation capacity, ductility, stiffness degradation, and other performance indexes. It has been determined from the results that under horizontal low-cycle repeated loading, the main failure cracks of the desert-sand AAC block wall constrained by the precast integral construction column are intersecting oblique cracks, and the cracks in wall failure penetrate along concrete blocks. The stiffness degradation rate of the wall constrained by the water-resistant gypsum construction column gradually decreases with increasing vertical compressive stress. The wall constrained by the water-resistant gypsum construction column with arranged steel bars has a desirable ductility. Under the same vertical compressive stress, the wall constrained by the water-resistant gypsum precast construction column with arranged steel bars has a significant energy dissipation capacity from cracking to the ultimate state. (4) A restoring force model is built for desert-sand AAC block walls constrained by the precast integral construction column using a three-fold line model, offering technical support for the elastoplastic seismic analysis of structures. [ABSTRACT FROM AUTHOR]

The aim of the current study is to evaluate the effectiveness of the watershed management operations by using the quantitative values obtained from the field survey in Khor-Sefidarak, Fashand, and Azimiyeh watersheds, and indicating a clear result of deposited sedimentation rate and vegetation improvement in reservoir tank of the structures. Field evaluation of watershed management structures showed that since 1991, a total of 652 gabion structures, 20 masonry structures, 533 small stone structures, and 15 embankment dams have been implemented in Khor-Sefidarak, Fashand, and Azimiyeh watersheds of Alborz province. A study of the stability of the structures showed that masonry structures had the most stability with the least need for restoration (92% of them). Also, 80% of gabion structures and 83% of small stone structures in the studied watersheds were stable. The study of sediment deposition in reservoirs tanks of structures in the study area showed that a total of 332,100 m3 of sediment has been deposited and stabilized by the structures and has prevented its transferring to rural and urban residential areas. Of this amount, 45960 m3 have been deposited by embankment dams and 286140 m3 by masonry structures, gabion and small stone structures. Sediment volume to structure volume index showed that it was 4.4, 15.3, and 1 for gabion, masonry, and small stone structures, respectively. Evaluation of vegetation and tree cover development of whining reservoirs tanks of watershed structures showed that 4880 trees and seedlings (97% of all them) have been grown and developed in the reservoirs of gabion structures. If the gabion structures are constructed, it is suggested that they be constructed in non-stone beds, and cement cover be used to prevent their destruction.

Biogeotechnology is an interdisciplinary technology to serves engineering by controlling the mineralization process of microorganisms. It has become one of the hot research topics in geotechnical engineering and related disciplines in recent years. Based on the application achievements of biogeotechnology in the restoration of masonry structures, this paper reviews the microbial mineralization reaction mechanisms and influencing factors, and summarizes the research results from the two construction techniques of surface bio-deposited layer and sealing reinforcement of masonry. The results show that biogeotechnology is feasible in the restoration and protection of masonry structures, and can effectively improve the physical and mechanical properties of restorations. It has the advantages of environmental friendliness and controllable reactions. However, large-scale applications in this field are relatively rare, which need to be further discussed and investigated in combination with indoor and outdoor experiments. [ABSTRACT FROM AUTHOR]

Rehabilitation and strengthening of existing masonry structures can improve their safety, prolong life and save economic costs. In this study, a total of eighteen masonry column specimens strengthened by ultra-high performance concrete (UHPC) were fabricated and tested in compression. The effects of strengthening method, strengthening thickness and loading eccentricity were investigated. The failure mode, bearing capacity, strain, ductility, and energy dissipation were discussed in before and after strengthening to evaluate the UHPC strengthening effectiveness. A three-dimensional numerical model established using finite element analysis (FEA) was validated with the experimental results. Results indicated that the brittle failure of masonry columns in compression could be significantly avoided using UHPC strengthening. Among three methods of strengthening, hoop strengthening was the most effective in increasing the ultimate load, ductility, and dissipated energy of masonry columns by 185.81%, 49.09%, and 297.12%, respectively. With the strengthening thickness increased from 0 to 20 and 30 mm, the ultimate bearing capacity of masonry columns was respectively increased by 29.17% and 117.26%, while the corresponding lateral displacement was decreased by 32.44% and 37.24%, respectively. The horizontal buckling of masonry columns can be relieved by UHPC, and the increase in eccentricity did not weaken the contribution of UHPC in strengthened masonry columns. The numerical results were in good agreement with the test results, with errors below 7.6%.

Arches and vaults are typical elements of ancient buildings. They are formed by voussoirs that resist the pressure they receive and transmit them through compression forces. The transmission of these forces justifies their curved shape. For this reason, arches and vaults are omnipresent elements in ancient constructions, all of them masonry structures. However, when visitors enter the Basilica of the Monastery of El Escorial, they find a narthex with a flat or planar vault. This vault is located under the floor of the choir loft. Its geometric characteristics and its shape, with no curvature, make it an architectural anomaly and a brilliant solution within masonry structures. Therefore, this article tries to analyse the construction process and structural behaviour of this vault, to understand its operation and how it remains standing five hundred years after its construction.

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.)

The Tower of Hercules is an icon of the city where it is located, A Coruña, and it is supposed to be the world's only surviving Roman lighthouse. Its function continues today: it provided a warning to shipping in antiquity and continues to do so now, in the 21st century. Furthermore, it is a paradigmatic case of architectural intervention in an ancient monument: in the 18th century, the Spanish engineer Eustaquio Giannini restored the tower, applying scientific criteria and maintaining the authenticity of the monument. For all these reasons, the Tower of Hercules is an exceptional benchmark through which the development and evolution of the different signaling and navigation aid systems can be studied from the beginning of our era to the present day. [ABSTRACT FROM AUTHOR]

Since masonry structures are prone to collapse in earthquakes, a novel joint reinforcement method with a polypropylene band (PP-band) and cement mortar (CM) has been put forward. Compared with the common reinforcement methods, this method not only facilitates construction but also ensures lower reinforcement cost. To systematically explore the influence of joint reinforcement on the seismic performance of masonry walls, quasi-static tests were carried out on six specimens with different reinforcement forms. The test results show that the joint action of PP-band and CM can significantly improve the specimen's brittle failure characteristics and enhance the integrity of the specimen after cracking. Compared with the specimen without reinforcement, each of the seismic performance indexes of the joint reinforced specimen had obvious improvement. The maximum increased rate about peak load and ductility of the joint reinforced specimen is 100.6% and 233.4%, respectively. [ABSTRACT FROM AUTHOR]

In the method of rectifying the inclination of inclined buildings, it's of nice significance to review the deformation kind of the muse of buildings within the course of back inclination. During this thesis, consistent with the characteristics of foundation deformation within the method of reverse tilting of building, the speculation of foundation balance axis correction is proposed, and therefore, the determination technique of dominant movement of the foundation balance axis is given. Supported by the foundation balance axis theory, a shallow excavation of masonry structure is employed to guide the work. By comprehensively mistreatment MATLAB and alternative processing computer code, through drawing the relative elevation surface of the axis, the relative elevation curve of the axis on either side of the building and therefore the deformation of the axis, the correction impact of the muse balance axis theory is analyzed from multiple angles, to finish the correction work of the entire project. The results show that the planned theory can do the safe come back of the building and supply technical support for the development correction project. [ABSTRACT FROM AUTHOR]

Polyurea elastomer has unique molecular structure, good energy absorption characteristics and excellent mechanical properties in terms of tear strength, tensile strength and breaking elongation. A large number of studies have shown that polyurea elastomer can effectively reduce the destructiveness of the structure under explosive load. Therefore, the research on polyurea elastomer relating to blast protection is becoming more and more extensive. In this paper, the microstructure of polyurea elastomer was briefly introduced, and its mechanical properties at different strain rates were described. Besides, based on the excellent mechanical properties of polyurea elastomer, the research progress of polyurea elastomer relating with blast protection was reviewed from the aspects of masonry structure and steel structure. The analysis showed that polyurea elastomers would become a research hotspot in blast protection field due to their excellent mechanical properties and good energy absorption characteristics and would have broad development prospects in practical engineering applications.

This study addresses the urgent need for retrofitting masonry schools in Iran, where over 89 % of schools are constructed using masonry (107000 Schools consisted of 563000 classrooms). Focusing on seismic performance evaluation, this research is of paramount importance as the current state of these schools poses a significant risk to the safety of millions of students. Without proper evaluation, the consequences could be catastrophic. To illustrate the significance of this study, a confined masonry school in Tehran was selected as a representative case study. The seismic resilience index was calculated, considering two hazard levels (2 % and 10 %) over a 50-year period, with and without near-fault pulse-type ground motions. Furthermore, a comparative analysis was conducted by modeling the retrofitted structure, which involved the application of shotcrete on walls, to assess the benefits of retrofitting. The seismic resilience index, derived from analytical functions that account for probable hazards and the recovery process, serves as a comprehensive measure of the structure's vulnerability. Through this evaluation, valuable insights into the retrofitting and rehabilitation of confined masonry schools can be gained. The results obtained from this research will aid in informed decision-making regarding the mitigation of seismic risks in similar structures. In conclusion, this paper indicates applying shotcrete to masonry walls can be substantially efficient as the resilience index and functionality of the building increases by a significant margin. Furthermore, the building damage was halved after the retrofitting operation and fragility curves admit it by showing better performance in higher drift ratios. • School resilience evaluation addresses a significant risk to the safety of millions of students. • More than 89 % of schools in Iran are assigned to masonry buildings. • Seismic performance assessment of the masonry building. • Performance-based engineering considering the limit states of the building. [ABSTRACT FROM AUTHOR]

Focusing on the seismic strengthening of masonry structure under tropical marine corrosion environment, a new method of strengthening masonry structure with FRP materials was proposed. Shaking table tests were carried out on a 1:4 scale volcanic rock masonry building model without and with FRP reinforcement respectively. The failure phenomena, dynamic characteristics, acceleration response and displacement response of unreinforced and reinforced volcanic stone masonry structures were analyzed. The test results show that the FRP reinforcement method delays the stiffness degradation of the structure under severe earthquakes, increases the integrity of the masonry structure, and effectively improves the deformation capacity of the masonry structure. The seismic performance of masonry structure strengthened with FRP is significantly better than that of masonry structure without reinforcement, which can greatly reduce the damage of masonry structure under severe earthquakes. [ABSTRACT FROM AUTHOR]

In the case of fire, ordinary mortar as the external plastering layer of masonry structure is prone to explosive peeling at high temperature. Therefore, the hybrid fiber reinforced engineered cementitious composites (HECC) is used to replace the ordinary mortar plastering to strengthen masonry structure, so as to improve the mechanical properties of the masonry structure and the adhesion with the reinforcement layer. In this paper, PB-HECC (mixed with PVA and basalt fibers) and PS-HECC (mixed with PVA and steel fibers) are used to improve the mechanical properties after high temperature, prism compression test and triple shear test are carried out at different temperatures. The test results show that the bonding performance of the engineered cementitious composites (ECC) reinforcement layer is much better than that of ordinary mortar. When the temperature is less than 200°C, the reinforcement layer mixed with basalt fiber (PB group) or steel fiber (PS group) has a higher bearing capacity. PB group has strong energy consumption capacity, but its shear strength decreases the most; When the temperature exceeds 200°C, PS group has the highest compressive capacity, shear bearing capacity and deformation capacity, maintaining relatively good residual mechanical properties. [ABSTRACT FROM AUTHOR]

This paper proposes an automated approach to predict crack pattern similarities that correlate well with assessment by structural engineers. We use Siamese convolutional neural networks (SCNN) that take two crack pattern images as inputs and output scalar similarity measures. We focus on 2D masonry facades with and without openings. The image pairs are generated using a statistics-based approach and labelled by 28 structural engineering experts. When the data is randomly split into fit and test data, the SCNNs can achieve good performance on the test data ( R 2 ≈ 0.9). When the SCNNs are tested on "unseen" archetypes, their test R 2 values are on average 1% lower than the case where all archetypes are "seen" during the training. These very good results indicate that SCNNs can generalise to unseen cases without compromising their performance. Although the analyses are restricted to the considered synthetic images, the results are promising and the approach is general. [ABSTRACT FROM AUTHOR]