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Recently, frequent flood disasters in China have seriously threatened economic development and public safety. This paper addresses the need for a dynamic urban flood emergency knowledge management system in emergency management departments and the lack of systematic knowledge among emergency managers regarding urban flood control. A multimodal knowledge graph-based urban flood emergency knowledge management model was constructed to enhance the decision-making capabilities of emergency management departments, improve the efficiency of public emergency evacuation, and reduce losses from urban flood disasters by analyzing the shortcomings of the existing emergency management system. An intelligent and dynamic flood emergency knowledge management model was built. This paper integrates multimodal knowledge graph technology to establish a multimodal emergency knowledge management framework for urban flood control. It develops and simulates the proposed model's application scenarios for urban flood emergency evacuation using the Flocking algorithm on the NetLogo platform. Through simulation experiments, the practicality and effectiveness of the model in real flood disaster situations were examined, particularly in simulating crowd evacuation behavior. The study found that the model significantly improves the accuracy of information and decision-making speed during emergency responses and supports emergency management departments in conducting targeted and personalized emergency decisions. This research provides a scientific basis for emergency management departments to optimize their emergency response strategies to flood disasters and serves as a reference and example for the application of multimodal knowledge graph technology in emergency management. [ABSTRACT FROM AUTHOR]

Pedestrian evacuation is an important measure to ensure disaster safety in central retail districts, the efficiency of which is affected by the synergy of road network planning indices. This paper established the typical forms of central retail district (CRD) road networks in terms of block form, network structure and road grade, taking China as an example. The experiment was designed using the orthogonal design of experiment (ODOE) method and quantified the evacuation time under different road network planning indices levels through the Anylogic simulation platform. Using range and variance analysis methods, the synergy of network density, network connectivity, road type and road width on pedestrian evacuation efficiency were studied from the perspectives of significance, importance and optimal level. The results showed that the type of CRD will affect the importance of network planning indices, and that the network connectivity is insignificant (P 0.477/0.581) in synergy; networks with wide pedestrian primary roads (30.1~40.0 m), medium secondary roads (3.1~5.0 m/side) and high density (11.0~13.0 km/km2) have the highest evacuation efficiency. From the perspective of evacuees, this paper put forward urban design implications on CRD road networks to improve their capacity for disaster prevention and reduction. [ABSTRACT FROM AUTHOR]

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]

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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.)

A calamitous landslide happened at 22:00 on September 1, 2014 in the Yunyang area of Chongqing City, southwest China, enforcing the evacuation of 508 people and damaging 23 buildings. The landslide volume comprised 1.44 million m3 of material in the source area and 0.4 million m3 of shoveled material. The debris flow runout extended 400 m vertically and 1600 m horizontally. The Xianchi reservoir landslide event has been investigated as follows: (1) samples collected from the main body of landslide were carried out using GCTS ring shear apparatus; (2) the parameters of shear and pore water pressure have been measured; and (3) the post‐failure characteristics of landslide have been analyzed using the numerical simulation method. The excess pore‐water pressure and erosion in the motion path are considered to be the key reasons for the long‐runout motion and the scale‐up of landslides, such as that at Xianchi, were caused by the heavy rainfall. The aim of this paper is to acquired numerical parameters and the basic resistance model, which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere. [ABSTRACT FROM AUTHOR]

With the development of office forms, the space form of super high-rise office buildings changed from the unitary efficient office space to a complex space that integrated office, communication, and experience, which also diversified the design of typical floors in the office zone. However, from the perspective of fire prevention, the placement of shared space changed the form of the plane in typical floors in the office zone, affecting the smoke spreading of fire and paths of personnel evacuation. Hence, the subject on the planar relationship among high-rise office buildings based on fire prevention analysis, which optimizes space design, is worthy of discussion. After collecting many cases of super high-rise office buildings in China, this study categorized them into six typical planes and adopted the software PyroSim for comparative simulation of the smoke spreading of fire. By comparing the visibility of different zones in fires, this study analyzed the effects of the area of the office zone, the location of the atrium, and the form of the plane on the fire visibility on the typical floor and put forth the key factors that influence fire visibility, thus optimizing the plane design of the typical floor of super high-rise buildings. The findings show that in the six fire scenes, the area of the office zone is between 1136m2 and 1736m2. The peak of duration for visibility decline at 1.5 m appeared in Scene 3. Its office zone is 1536m2, and the duration of visibility decline is greater than 1000 s. In other fire scenes, the duration of visibility decline is less than 300 s. By comparing the plane arrangement features of the fire scenes, the paper concludes that in a given fire scene, establishing an atrium in the office zone, expanding the length of the adjacent edge between the atrium and the office zone, and building an evacuation corridor between the atrium and the core tube can greatly extend the effective evacuation time. This can serve as reference for the plane design of super high-rise office buildings. [ABSTRACT FROM AUTHOR]

Purpose - To model the evacuation time from buildings in the event of emergencies based on occupant load, looking specifically at the exit width as a design parameter. Design/methodology/approach - In this study, transient occupant loads from a simulation model based on a recent study of 34 offices in Hong Kong were used to evaluate the probable risk to evacuees in the case of an emergency evacuation. For this analysis the "door carrying capacity" approach was used, together with probability profiles for the occupant loads at certain exit flow rates. This paper investigates the occupant load profiles as well as the yearly and daily occupant load variations of some typical offices in Hong Kong and examines the fire safety implications of the office building designs from the perspective of the risk to evacuees. Findings - The results show that the building occupant load, occupant-load ratio, total exit width and specific flow rate at the exit significantly affect the risk to evacuees. Research limitations/implications - The model parameters are not exhaustive and are determined from surveys in Hong Kong. Practical implications - A useful source of reference in conducting risk assessment for safe egress design of office buildings for those involved in building design, operation and management. Originality/value - This paper, taking account of exit design, occupant load and its variations using the door carrying capacity approach, presents a simple method to determine the probable risk to evacuees in offices. [ABSTRACT FROM AUTHOR]

Abstract: In China, both the mountainous areas and the number of people who live in mountain areas occupy a significant proportion. When production accidents or natural disasters happen, the residents in mountain areas should be evacuated and the evacuation is of obvious importance to public safety. But it is a pity that there are few studies on safety evacuation in rough terrain. The particularity of the complex terrain in mountain areas, however, makes it difficult to study pedestrian evacuation. In this paper, a three-dimensional surface cellular automata model is proposed to numerically simulate the real time dynamic evacuation of residents. The model takes into account topographic characteristics (the slope gradient) of the environment and the biomechanics characteristics (weight and leg extensor power) of the residents to calculate the walking speed. This paper only focuses on the influence of topography and the physiological parameters are defined as constants according to a statistical report. Velocity varies with the topography. In order to simulate the behavior of a crowd with varying movement velocities, and a numerical algorithm is used to determine the time step of iteration. By doing so, a numerical simulation can be conducted in a 3D surface CA model. Moreover, considering residents evacuation around a gas well in a mountain area as a case, a visualization system for a three-dimensional simulation of pedestrian evacuation is developed. In the simulation process, population behaviors of congestion, queuing and collision avoidance can be observed. The simulation results are explained reasonably. Therefore, the model presented in this paper can realize a 3D dynamic simulation of pedestrian evacuation vividly in complex terrain and predict the evacuation procedure and evacuation time required, which can supply some valuable information for emergency management. [Copyright &y& Elsevier]

Indoor fire is a sudden and frequent disaster that severely threatens the safety of indoor people worldwide. Indoor fire emergency evacuation is crucial to reducing losses involving various objects and complex relations. However, traditional studies only rely on numerical simulation, which cannot provide adequate support for decision-making in indoor fire scenarios. The knowledge graph is a knowledge base that can fully utilize massive heterogeneous data to form a sound knowledge system; however, it has not been effectively applied in the fire emergency domain. This study is a preliminary attempt to construct a knowledge graph for indoor fire emergency evacuation. We constructed the indoor fire domain ontology and proposed a four-tuple knowledge representation model. A knowledge graph was constructed with 1852 nodes and 2364 relations from 25 indoor fire events. The proposed method was tested for the case study of Henan Pingdingshan '5.25' Fire Accident in China. Results show that the proposed knowledge representation model and the corresponding knowledge graph can represent complicated indoor fire events and support indoor fire emergency evacuation. [ABSTRACT FROM AUTHOR]

It is well known that a large percentage of occupants in a building are evacuated together with their friends, families, and officemates, especially in China. Small group behaviors are therefore critical for crowd movement. This paper aims to study the crowd dynamic considering different social relations and the impacts of small groups on crowd dynamics in emergency evacuation. Three experiments are conducted in an 11-storey office building. In the first two experiments, all participants are classmates and know each other well. They are evacuated as individuals or pairs. In the third experiment, social relations among the participants are complex. Participants consist of 8 families, 6 lovers and several individuals. Space–time features, speed characteristics and density–speed relations for each experiment are analyzed and compared. Results conclude that small group behaviors can make positive impacts on crowd dynamics when evacuees know each other and are cooperative. This conclusion is also testified by four verified experiments. In the third experiment, speeds of evacuees are lowest. Small groups form automatically with the presence of intimate social relations. Small groups in this experiment slow down the average speed of the crowd and make disturbance on the crowd flow. Small groups in this case make negative impacts on the movement of the crowd. It is because that evacuees do not know each other and they are competitive to each other. Characteristics of different types of small groups are also investigated. Experimental data can provide foundational parameters for evacuation model development and are helpful for building designers. [ABSTRACT FROM AUTHOR]

Due to the fact that escape panics are unexpected and dangerous, which excludes real-life experiments because of technical difficulties and ethical reasons, the evacuation simulations in real-life disasters are still rare. In this paper, the escape panics of classroom evacuation in real-life 2013 Ya’an earthquake in China are simulated and reproduced using the social force model. Firstly, a robust differential evolution (DE) is employed to calibrate and optimize the parameters of social force model to achieve a desired nonlinear evacuation speed which is consistent with real-life video data. It is demonstrated the DE-calibrated social force model can reproduce the characteristics of pedestrian flow in the real-life earthquake evacuation including the nonlinear evacuation speed curve and the pedestrian position distributions at different time. Moreover, the trained evacuation leader has remarkable impact on the evacuation process which can be beneficial to maintain the calm and order of crowd, decrease the desired velocity of crowd, and thus avoid fatal accident to the most degree. Finally, different layouts of classroom have similar evacuation efficiency because different internal layouts can only change partial flow of pedestrians in the left and right corridors, and total flow aggregating in the exit of classroom is still unchanged. However, total evacuation time can be sharply reduced to 17 s from above 36 s, and evacuation efficiency has almost doubled when the back door is open, which means we should try to keep all the emergency exits open in order to provide the crowd with more chances to escape when disasters occur. [ABSTRACT FROM AUTHOR]

With the rapid increasing mileage of China's long-distance oil and gas pipelines, the intersection construction with other civil engineering, encroachment by invading the pipeline route, and other third-part problems occurred occasionally. Heavy vehicles rolling the serving pipeline have become one of the inevitable safety risks. The field test method of three in-service long oil and gas pipelines under heavy vehicle rolling is elaborated. The pipeline stress and soil pressure during tests are monitored and analyzed. The parametric model of pipe mechanical response under heavy vehicle rolling and stacking load is established, and the quantitative feedback of each parameter on pipeline stress safety response under heavy vehicle rolling is formed. The results show that the influence factors such as vehicle weight, vehicle speed, buried depth of pipeline, horizontal distance and cover plate on the stress state, vertical displacement state, and contact stress of pipe soil interface are highly consistent with the finite element method and test method, which could be a guideline for the safety assessment at rolling site. [ABSTRACT FROM AUTHOR]

Study of evacuation from fire is always focused on evacuation models, but rarely on evacuation experiments. This paper presents the results acquired from an announced evacuation drill of XIN LIAN XIN Store in China. There are two floors and five emergency exits in the building. Most of the customers knew there would be an evacuation drill before they entered the store, but they did not know the exact beginning time. The video of the whole evacuation process was recorded using television cameras installed in the store. The customers who evacuated from the store were asked to complete a questionnaire by researchers positioned outside the five exits. Analysis of the videotapes provided information on total evacuation time and actual number of customers who evacuated from the store. Questionnaires present the information on customer characteristics, primary behavior at alarm, pre-movement time and exit choice. The analysis results show that pre-movement time is an important part of evacuation process. Strengthening detector, alarm equipments and staff training are very effective and necessary for fire safety in China. These data can also be used as input parameters for evacuation models in performance-based fire protection design or validating the evacuation models'' accuracy. [Copyright &y& Elsevier]

The post-disaster emergency rescue and loss evaluation hinges on the timeliness and accuracy of safety assessment of building structures in quake-hit regions. At present, the damage identification of quake-hit buildings in China is mainly conducted based on the experience of the experts. Such an assessment method will inevitably lead to the differences in identification results because each expert has his/her own subjective understanding of the degree of structural damage. In order to solve this problem, the low cyclic loading test of 7 specimens of shear wall is conducted and the hysteretic curves of seven shear walls are drawn. The failure modes and seismic performance of members under different design parameters (axial compression ratio of shear wall, shear span ratio, form of edge member, reinforcement ratio, stirrup ratio of coupling beam, and span height ratio) are compared. By recording the damage images taken at the controlled displacement under each level of load, the corresponding damage indexes are calculated, and the correspondence between the typical component damages and the damage indexes is discovered. After that, the images are compiled into an atlas. The authors calculate the damage index of the overall structure based on the damage indexes of the components and carries out damage identification of RC shear wall structure with the said damage index. [ABSTRACT FROM AUTHOR]

Due to the casualties and economic losses that can be caused by building collapse after an earthquake, building damage assessment is a very important part of earthquake disaster evaluation. As a result of the advantages of polarimetric synthetic aperture radar (PolSAR) imaging, both the accuracy and speed of the damage assessment can be guaranteed in the process of building damage identification using a single post-earthquake PolSAR image. The number of collapsed buildings is usually overestimated when adopting the traditional method, which is because the scattering mechanism is similar to that of intact oriented buildings. In view of this, the variable coefficient of angle domains based on the Fourier amplitude spectrum parameter (CV_AFI) is proposed to ameliorate the damaged building overestimation. By combining the improved Yamaguchi four-component decomposition method with the CV_AFI parameter, the proposed method can be used to extract building damage information from a single PolSAR image. With the Ms 7.1 Yushu earthquake in China as the research case, compared with the traditional method, the producer's accuracy of the proposed method for undamaged buildings was increased by 38.87%. The proposed method can obtain a higher accuracy of building damage information extraction and significantly reduce building damage overestimation. [ABSTRACT FROM AUTHOR]

The construction industry is experiencing remarkable growth in the data generation. Data mining (DM) from considerable amount of data in the construction industry has emerged as an important tool for knowledge discovery. Despite the remarkable growth of DM applications to the construction industry, a systematic review on DM applications in this field is still lacking. Therefore, this paper attempts to provide a comprehensive literature review of DM application articles published between 2001 and 2019 with the specificity of construction industry. The popularity of DM applications in the construction industry is increasing, especially after 2016, with a plurality emanating from China. The main data sources, DM functions, and frequently used DM techniques in the construction industry are discussed in detail. Nine major application fields are identified, with the primary research interests focusing on multiple dimensions of energy, safety management, building occupancy and occupant behavior, material performance, and textual knowledge discovery. Four major challenges and four future research directions are proposed by drawing on the research findings. This study provides academics and practitioners with a more comprehensive understanding of the state-of-the-art of DM applications and heuristic implications for future studies. • A comprehensive review of data mining (DM) application in construction industry from 2001 to March 2019 is conducted. • The popularity of DM applications in construction industry is increasing, especially after 2016. • 9 major application fields are identified and comprehensively analyzed. • Four challenges and four future directions are proposed. [ABSTRACT FROM AUTHOR]

The prefabricated building as a major initiative has been put forward by China in recent years to promote the transformation and upgrading of the construction industry, but its rapid development also faces high cost constraints. Therefore, it is necessary and urgent to study the key cost drivers and cost control paths of prefabricated buildings. Most of the current research focuses on the construction cost of prefabricated building as a static object. This article, on the other hand, regards the construction cost of prefabricated building as a dynamic formation process and conducts systematic research from product systems, technical systems, construction processes, and management modes. The influence factors of prefabricated building cost are defined and screened with the help of HSM and previous research results. A cause-and-effect model and cost control model of prefabricated building cost driver are established. Based on the model test of the actual project, the cost generation of prefabricated buildings is simulated. Through sensitivity analysis, key cost drivers of prefabricated building are identified and ranked as degree of design standardization, unit price, prefabrication rate, information technology level, transportation mode, labor level, machinery level, transportation distance, etc. Accordingly, corresponding strategies are proposed for the cost control of prefabricated buildings. [ABSTRACT FROM AUTHOR]

A delay in the pre-evacuation reaction may be one of the reasons causing occupants to be ‘trapped’ in a dangerous zone. Under fire situations, people are found to behave differently in that some may start evacuation immediately, some may ignore the fire alarms and engage in their activities and some others may participate in fighting the fire. These behavioral reaction patterns are influenced by some factors, such as occupant characteristics, building characteristics and fire characteristics. The purpose of this study is to investigate the pre-evacuation behavior of occupants under fire and explore the associations between these factors and the human behavior. To obtain the human behavioral information in real fire, a post-fire survey for a multi-storey office building fire in a major city in Mainland China was carried out with the assistance of local fire professionals. Some of the possible factors that might influence the occupants’ actions at recognitions and response stage were examined. It was reckoned that the behavioral reaction at recognition and response stage was mainly dependent on the human characteristics and building characteristics except the fire characteristics. The results also implied that pre-evacuation time was typically influenced by the occupant characteristics. [ABSTRACT FROM AUTHOR]