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在分析DRASTIC方法的基础上,结合前人研究成果,运用层次分析法构建了二层评价指标体系,并结合多层次模糊评价理论,建立了基于层次分析的DRASTIC二层模糊评价模型,并将该模型应用到曲靖盆地地下水脆弱性评价中。结果表明,该模型评价灵敏度高,更能反映地下水脆弱性的空间连续性,且该模型计算方法较简便,进一步丰富了地下水脆弱性的评价方法。 相似文献
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Tiago Miguel FERREIRA Jo o EST V O Rui MAIO Romeu VICENTE 《Frontiers of Structural and Civil Engineering》2020,14(3):609
This paper discusses the adoption of Artificial Intelligence-based techniques to estimate seismic damage, not with the goal of replacing existing approaches, but as a mean to improve the precision of empirical methods. For such, damage data collected in the aftermath of the 1998 Azores earthquake (Portugal) is used to develop a comparative analysis between damage grades obtained resorting to a classic damage formulation and an innovative approach based on Artificial Neural Networks (ANNs). The analysis is carried out on the basis of a vulnerability index computed with a hybrid seismic vulnerability assessment methodology, which is subsequently used as input to both approaches. The results obtained are then compared with real post-earthquake damage observation and critically discussed taking into account the level of adjustment achieved by each approach. Finally, a computer routine that uses the ANN as an approximation function is developed and applied to derive a new vulnerability curve expression. In general terms, the ANN developed in this study allowed to obtain much better approximations than those achieved with the original vulnerability approach, which has revealed to be quite non-conservative. Similarly, the proposed vulnerability curve expression was found to provide a more accurate damage prediction than the traditional analytical expressions. 相似文献
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文章以桂林规划中心城区为例,利用地质环境要素通过层次分析法(AHP)对岩溶塌陷易损性进行评价,并通过MapGIS软件实现可视化。选取了人口密度、城市规划用地用途及道路用途3个影响岩溶塌陷易损性的地质环境因素,建立了岩溶塌陷易损性评价指标体系和评价方法,并对研究区进行了评价,依据预测分区指标计算,研究区岩溶塌陷易损分区结果为高易损区的面积约174.27 km^2;中易损区的面积约41.10 km^2;低易损区的面积约243.45 km^2;非易损区面积约421.18 km^2。 相似文献
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为研究地铁施工风险耦合机理和地铁施工系统的脆弱性,提高地铁施工系统的安全性。结合脆弱性理论,归纳地铁施工安全风险因素,构建系统脆弱性模型;并对国内2008-2020年的地铁施工事故进行搜集整理,选取风险致因因素完整的130起事故,运用N-K模型计算不同耦合方式下的风险发生概率以及风险耦合值,获得影响系统脆弱性的关键风险耦合方式。结果表明:系统中的风险因素越多,事故发生的概率越大;人员因素、管理因素与环境因素完全耦合时,地铁施工安全系统脆弱性较大。研究明确系统中脆弱性的关键耦合风险,为地铁施工安全控制方面提供了参考价值。 相似文献
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Mark G Stewart 《Journal of Wind Engineering & Industrial Aerodynamics》2003,91(5):671-691
A risk analysis procedure is developed to predict economic risks due to changes to existing housing vulnerability over time. The wind hazard and building vulnerability models are based on exposure of residential construction to cyclones in North Queensland, Australia. A feature of the building vulnerability model is that it includes the effect of enhanced (post-1980) building standards in North Queensland. A cyclone damage risk-cost-benefit analysis is then used to assess the economic viability of strengthening existing houses to post-1980 construction quality for temporal changes in economic risks for two scenarios: (i) retrofitting pre-1980 houses to post-1980 quality immediately after they experience cyclone damage, or (ii) rate of growth of the proportion of post-1980 construction. The cost of retrofit or additional cost of strengthened construction can be included in the risk analysis to help assess the economic viability of these and other scenarios. Results are given in terms of annual and annualised economic risks and the damage loss conditional on occurrence of an Average Recurrence Interval event. The annualised economic risk is a time-variant measure of risk that is influenced by temporal changes in building vulnerability, which can be used to help determine the time when a particular strengthening strategy will be economically viable. “Zones of economic viability” determine the potential for cost-effective retrofitting of residential construction. The risk analysis also enabled the time to economic viability to be calculated. 相似文献
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The groundwater vulnerability to the pollution assessment was considered as an efficient tool to limit and to control its quantitative and qualitative degradation risks. The DRASTIC high, moderate and low groundwater vulnerability zones of the Sfax–Agareb basin (Tunisia) cover about 10, 29 and 61% of the study area, respectively. The validation of the DRASTIC vulnerability map was undertaken through comparison of areas of high nitrate concentration and their relative vulnerability index. The DRASTIC vulnerability map illustrates a good rate of coincidence between the nitrate concentration ranges and the various vulnerability classes as recognized by statistical analysis. The reliability of the final vulnerability map has been tested, showing a general positive trend relating the mean nitrate concentration in the wells to their relative vulnerability classes (R2=0.88). When correlating the 214 available groundwater nitrate concentrations to the DRASTIC index in these wells location, a significant positive correlation with Cor=0.55 was found. 相似文献
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Up to now, reuse and recycling of existing buildings have not been examined widely. This paper discusses the theories, methods and practicalities of buildings' end of life with a main focus on planning and managing reuse and recycling of existing buildings. Our aim is the realistic modelling of theoretical scenarios for end of life based on a case study. The methods of building survey, material classification and documentation for reuse, recycling and disposal of existing constructions are presented. Investigations and calculations were done on an existing cottage in the Alps. The ecologically most beneficial disposal phase of the old wooden hut is our main objective. Critical questions arise from the quality of the material and how it can be extracted, separated and balanced in an appropriate way. A systematic survey of the building by inspection of constructions and materials in iterative steps allows a detailed material balance with condition and property information. This information is crucial for scenarios and material flow analysis of demolished and rebuilt building in environmental system analysis. For future planning, the reuse and recycling of existing buildings should be integrated quite early in the planning process so that we can use the materials in the best way. 相似文献
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Vincenzo Sapienza 《土木工程与建筑:英文版》2014,(9):1138-1144
The colonization of Sicilian latifundium was an attempt of regeneration of the rural areas. It was carried out by Benito Mussolini, called II Duce, who governed Italy by a regime with an absolute and conservative approach for 20 years since 1922. According to this plan, there were some rural villages (with a school, a church, a police station and a doctor's surgery) and a number of rural homes, spread in the landscape, that formed one of the most important achievements of the agrarian reform in Italy. The author has been conducting scientific research on this topic for several years. He started with the archive "Ente per la Colonizzazione del Latifondo Siciliano" (now called Ente Sviluppo Agricolo) to review the original designs and contracts with companies, ledgers and other administrative documents. Lately, he has been reviewing the personal archives of designers involved in the building program, where he has found original drawings, letters, sketches, etc.. He has also conducted some architectonic and technical surveys of the sites. We have to consider that nowadays the mentioned rural villages are a strategic resource for the development of the neighboring areas, as it may become a network for the sustainable tourism and the promotion of the local agro food specialties. On this purpose, the local authority is going to promote some plans for the requalification of these sites. The particular achievement of this article is to show a number of possibilities for the reuse of these places. 相似文献
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Francisco Javier Gutierrez Garcia Pedro Perez Diaz Pedro Sanchez Luis 《土木工程与建筑:英文版》2014,(9):1145-1150
Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project and its cost. We show a model of linear entire mixed programming to solve the considered problem. The aim is to minimize the project total time, by means of the assignment of equipments of work to the different production lines of the activities to realizing. The fundamental beginning is to support the same production (rate of production in meters/day of the activity in view of the equipment of work) for tbe different equipments to achieve the maximum efficiency in each period of time. With the limited availability of resources, the work must be continuous and the period of time between operations and final must be kept. However, this paper also presents the bibliographical study on methodologies of the optimization of construction processes in response to the two objectives: time and cost. This will consider the use of recta-heuristic techniques, such as population based algorithms. 相似文献
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A new type of bridge called "butterfly web bridge" is under construction in Japan. In a butterfly web bridge, the butterfly-shaped web forms a structure that exhibits behavior similar to a double Warren truss. The 80 MPa concrete is used for the butterfly web which has a precast plate with a thickness of 150 mm. As butterfly web is a concrete material, reinforcement provided by prestressing tendons is needed on the tension side. Moreover, the 150 mm plate has no re-bars but is reinforced by steel fibers. This bridge, named Takubogawa Bridge, is a highway bridge and has 10 spans including the 87.5 m maximum span length. Takubogawa Bridge is constructed by flee cantilevering method. The butterfly web enables the construction speed of cantilevering to be advanced about 50% compared with conventional cast-in-situ method and can meet the requirement of light weight and low maintenance. 相似文献
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Quantitative assessment of groundwater vulnerability using index system and transport simulation, Huangshuihe catchment, China 总被引:1,自引:0,他引:1
Groundwater vulnerability assessment has been an increasingly important environment management tool. The existing vulnerability assessment approaches are mostly index systems which have significant disadvantages. There need to be some quantitative studies on vulnerability indicators based on objective physical process study. In this study, we tried to do vulnerability assessment in Huangshuihe catchment in Shandong province of China using both contaminant transport simulations and index system approach. Transit time of 75% of hypothetical injected contaminant concentration was considered as the vulnerability indicator. First, we collected the field data of the Huangshuihe catchment and the catchment was divided into 34 sub areas that can each be treated as a transport sub model. Next, we constructed a Hydrus1D transport model of Huangshuihe catchment. Different sub areas had different input values. Thirdly, we used Monte-Carlo simulation to improve the collected data and did vulnerability assessment using the statistics of the contaminant transit time as a vulnerability indicator. Finally, to compare with the assessment result by transport simulation, we applied two index systems to Huangshuihe catchment. The first was DRASTIC system, and the other was a system we tentatively constructed examining the relationships between the transit time and the input parameters by simply changing the input values. The result of comparisons between the two index systems and transport simulation approach suggested partial validation to DRASTIC, and the construction of the new tentative index system was an attempt of building up index approaches based on physical process simulation. 相似文献
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Daniel Cupertino Tatiana G. do Amaral Sammea A. Vilarinho Leonardo Alencar 《土木工程与建筑:英文版》2014,(4):477-485
The increase on the competitiveness, the search on the customer satisfaction, the search by reducing waste in the civil construction were facts which helped entrepreneurs and companies to seek new ways of working, being lean construction one of the ways to get that. Studies report that the application of the lean tools in construction was carried out in an isolated way. This type of application was pointed as a major factor limiting the extent of achievement in implementing lean principles. The aim of this studies is to identify opportunities to implement the principles of lean production in the service department of a construction company in Goi~is, proposing routines that try to implement the continuous improvement of its processes, eliminating waste, reducing the lead time, allow it to perform the mapping processes, applying the just-in-time and among others, providing services that add value to the customer satisfaction. It was possible to establish the average time for each step, allowing to identify possible improvements in the department, from the perspective of lean principles. The research paper concludes by pointing out the activities for the Department of Post Construction work from building companies, from lean concepts. 相似文献
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Successful and cost-effective construction relies upon appropriate communication of the participants of the construction project. Hence, it is important to define the rights and responsibilities of the parties, and relationships among them. In this context, well-designed and complete agreement is essential and necessary for the successfully completion of a construction project within the desired time, quality and budget. In this paper, it is aimed to analyze and compare the owner-contractor agreements in the Turkish and the US construction industry. First, the importance of construction contracts and contractual elements of an agreement is determined, and then, the standard owner-contractor agreement which is used in the Turkish construction industry is analyzed and compared with the US standard owner-contractor agreement. Finally, the differences between these agreements are put forward, the lack and deficiencies of Turkish standard agreement form are determined, and appropriate suggestions are improved. 相似文献
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This paper reports on the current state of an ongoing research project which is aimed at implementing intelligent models for hardly predictable hazard scenarios identification in construction sites. As any programmatic actions cannot deal with the unpredictable nature of many risk dynamics, an attempt to improve the current approach for safety management in the construction industry will be presented in this paper. To this aim, the features offered by Bayesian networks have been exploited. The present research has led to the definition of a probabilistic model using elicitation techniques from subjective knowledge. This model, which might be meant as a reliable knowledge map about accident dynamics, showed that a relevant part of occurrences fall in the "hardly predictable hazards" category, which cannot be warded off by programmatic safety measures. Hence, more effort turned out to be needed in order to manage those hardly predictable hazardous scenarios. Consequently, further developments of this research project will focus on a real time monitoring system for the identification of unpredictable hazardous events in construction. 相似文献