Optimizing Skyscrapers' Spatial Integrated DSF-MTMD System Under Wind Loads

Author(s):  
Oren Lavan ◽  
Liran Anaby

<p>From a structural engineering point of view, wind effects pose one of the major challenges to tall buildings. From a performance/architectural point of view, climatologic aspects pose a major challenge. Remedies for each challenge separately have been proposed. One of the remedies for wind effects is the Tunes-Mass-Damper (TMD) or multiple TMD's. To mitigate climatological issues, the Double-Skin-Façade (DSF) has been developed. Recently it has been suggested to take advantage of the space between the two skins of the DSF system to allocate TMD's.</p><p>In this work, another step is taken towards a single remedy for both challenges. A modified version of the TMD-DSF system proposed by Moon (2016) is presented. That is, parts of the mass of the DSF envelope itself are used as part of a multiple TMD (MTMD) system. This is obtained by connecting these parts to the building using springs and dampers while allowing the DSF to move parallel to the floor edges. Furthermore, the DSF-MTMD system is optimized using a formal optimization approach. The optimization indicates which parts of the envelope should be connected to the building rigidly and which should be used as TMD's. Furthermore, the properties of the springs and the dampers are determined by minimizing the cost associated with transforming the DSF system to a DSF-MTMD system and limiting wind responses to desired values.</p>

Author(s):  
Emil Simiu ◽  
Rene D. Gabbai

Current approaches to the estimation of wind-induced wind effects on tall buildings are based largely on 1970s and 1980s technology, and were shown to result in some cases in errors of up to 40%. Improvements are needed in: (i) the description of direction-dependent aerodynamics; (ii) the description of the direction-dependent extreme wind climate; (iii) the estimation of inertial wind effects induced by fluctuating aerodynamic forces acting on the entire building envelope; (iv) the estimation of uncertainties inherent in the wind effects; and (v) the use of applied wind forces, calculated inertial forces, and uncertainty estimates, to obtain via influence coefficients accurate and risk-consistent estimates of wind-induced internal forces or demand-to-capacity ratios for any individual structural member. Methods used in current wind engineering practice are especially deficient when the distribution of the wind loads over the building surface and their effects at levels other than the building base are not known, as is the case when measurements are obtained by the High-Frequency Force Balance method, particularly in the presence of aerodynamic interference effects due to neighboring buildings. The paper describes a procedure that makes it possible to estimate wind-induced internal forces and demand-to-capacity ratios in any individual member by: developing aerodynamic and wind climatological data sets, as well as aerodynamic/climatological directional interaction models; significantly improving the quality of the design via rigorous structural engineering methods made possible by modern computational resources; and properly accounting for knowledge uncertainties. The paper covers estimates of wind effects required for allowable stress design, wherein knowledge uncertainties pertaining to the parameters that determine the wind loading are not considered, as well as estimates required for strength design, in which these uncertainties need to be accounted for explicitly.


2018 ◽  
Vol 7 (2.2) ◽  
pp. 21
Author(s):  
Marzieh Jahani ◽  
Parastoo Mohammadi

This paper aims to present a model to determine the preferred Islamic contract for the bank facilities applicant in the industrial sector. For this purpose we use a consolidated method which includes the compromise solution multi-criteria optimization in the first phase, and the calculation of the cost of financing for the applicant of facilities in the second phase. Afterwards, by using the output of the both-phase, the preferred Islamic contract based on the combinational criterion has been determined for the applicant of the facilities. According to the fact that in the financing of the projects, in addition to the criteria related to the cost of financing, the qualitative criteria are also important, so both the qualitative and quantitative criteria have been considered in this research. In this study, we used four widely applied Islamic contracts (Jo’aalah Instalment sales, Hire purchase, Participation). The assessment criteria of the Islamic contracts have been extracted in the form of a questionnaire based on the previous studies and the expert’s point of view. In the first phase, the Analytic Hierarchy Process (AHP) has been used in order to determine the weights of the evaluation criteria of the Islamic contracts; and, in order to select an appropriate contract for the applicant, the compromise solution multi-criteria optimization approach (VIKOR), which is based on the decision matrix, was used. In the second phase, the cost of financing from the bank was estimated for the applicant of the facilities in the four contracts. Finally, the obtained results of the qualitative questionnaire and the cost of financing from the bank have been combined; thus, the preferred contract for the applicant of facilities has been determined based on a combinational criterion.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Nicola Longarini ◽  
Luigi Cabras ◽  
Marco Zucca ◽  
Suvash Chapain ◽  
Aly Mousaad Aly

The behavior of a very slender building is investigated under wind loads, to satisfy both strength and serviceability (comfort) design criteria. To evaluate the wind effects, wind tunnel testing and structural analysis were conducted, by two different procedures: (i) Pressure Integration Method (PIM), with finite element modeling, and (ii) High Frequency Force Balance (HFFB) technique. The results from both approaches are compared with those obtained from Eurocode 1 and the Italian design codes, emphasizing the need to further deepen the understanding of problems related to wind actions on such type of structure with high geometrical slenderness. In order to reduce wind induced effects, structural and damping solutions are proposed and discussed in a comparative study. These solutions include (1) height reduction, (2) steel belts, (3) tuned mass damper, (4) viscous dampers, and (5) orientation change. Each solution is studied in detail, along with its advantages and limitations, and the reductions in the design loads and structural displacements and acceleration are quantified. The study shows the potential of damping enhancement in the building to mitigate vibrations and reduce design loads and hence provide an optimal balance among resilience, serviceability, and sustainability requirements.


The article focuses on the problem of the lack of objective evaluation of space-planning arrangement of buildings as a creative approach of the architect to the performing of functional tasks by the object. It is proposed to create a methodology for assessing the functional of space-planning solutions of buildings on the basis of numerical simulation of functional processes using the theory of human flows. There is a description of the prospects of using this method, which makes it possible to increase the coefficient of compactness, materials and works saving, more efficient use of space, reduce the cost of the life cycle of the building, save human forces and time to implement the functional of the building. The necessary initial data for modeling on the example of shopping and shopping-entertainment centers are considered. There are three main tasks for algorithmization of the functional of shopping centers. The conclusion is made about necessity of development of a method for objective assessment of buildings from the point of view of ergonomics of space-planning decisions based on the study of human behavior in buildings of different purposes.


Author(s):  
Vitaly Lobas ◽  
◽  
Elena Petryaeva ◽  

The article deals with modern mechanisms for managing social protection of the population by the state and the private sector. From the point of view of forms of state regulation of the sphere of social protection, system indicators usually include the state and dynamics of growth in the standard of living of the population, material goods, services and social guarantees for the poorly provided segments of the population. The main indicator among the above is the state of the consumer market, as one of the main factors in the development of the state. Priority areas of public administration with the use of various forms of social security have been identified. It should be emphasized that, despite the legislative conflicts that exist today in Ukraine, mandatory indexation of the cost of living is established, which is associated with inflation. Various scientists note that although the definition of the cost of living index has a well-established methodology, there are quite a lot of regional features in the structure of consumption. All this is due to restrictions that are included in the consumer basket of goods and different levels of socio-economic development of regions. The analysis of the establishment and periodic review of the minimum consumer budgets of the subsistence minimum and wages of the working population and the need to form state insurance funds for unforeseen circumstances is carried out. Considering in this context the levers of state management of social guarantees of the population, we drew attention to the crisis periods that are associated with the market transformation of the regional economy. In these conditions, there is a need to develop and implement new mechanisms and clusters in the system of socio-economic relations. The components of the mechanisms ofstate regulation ofsocial guarantees of the population are proposed. The deepening of market relations in the process of reforming the system of social protection of the population should be aimed at social well-being.


Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 305
Author(s):  
Juan Yan ◽  
Marietta Haffner ◽  
Marja Elsinga

Inclusionary housing (IH) is a regulatory instrument adopted by local governments in many countries to produce affordable housing by capturing resources created through the marketplace. In order to assess whether it is efficient, scholarly attention has been widely focused on its evaluation. However, there is a lack of studies evaluating IH from a governance perspective. Since IH is about involving private actors in affordable housing production, the governance point of view of cooperating governmental and non-governmental actors governing society to achieve societal goals is highly relevant. The two most important elements of governance—actors and interrelationships among these actors—are taken to build an analytical framework to explore and evaluate the governance of IH. Based on a research approach that combines a literature review and a case study of China, this paper concludes that the ineffective governance of Chinese IH is based on three challenges: (1) The distribution of costs and benefits across actors is unequal since private developers bear the cost, but do not enjoy the increments of land value; (2) there is no sufficient compensation for developers to offset the cost; and (3) there is no room for negotiations for flexibility in a declining market. Given that IH is favored in many Chinese cities, this paper offers the policy implications: local governments should bear more costs of IH, rethink their relations with developers, provide flexible compliance options for developers, and perform differently in a flourishing housing market and a declining housing market.


Author(s):  
Iunio Iervolino ◽  
Pasquale Cito ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Antonio Vitale

AbstractShakeMap is the tool to evaluate the ground motion effect of earthquakes in vast areas. It is useful to delimit the zones where the shaking is expected to have been most significant, for civil defense rapid response. From the earthquake engineering point of view, it can be used to infer the seismic actions on the built environment to calibrate vulnerability models or to define the reconstruction policies based on observed damage vs shaking. In the case of long-lasting seismic sequences, it can be useful to develop ShakeMap envelopes, that is, maps of the largest ground intensity among those from the ShakeMap of (selected) events of a seismic sequence, to delimit areas where the effects of the whole sequence have been of structural engineering relevance. This study introduces ShakeMap envelopes and discusses them for the central Italy 2016–2017 seismic sequence. The specific goals of the study are: (i) to compare the envelopes and the ShakeMap of the main events of the sequence to make the case for sequence-based maps; (ii) to quantify the exceedance of design seismic actions based on the envelopes; (iii) to make envelopes available for further studies and the reconstruction planning; (iv) to gather insights on the (repeated) exceedance of design seismic actions at some sites. Results, which include considerations of uncertainty in ShakeMap, show that the sequence caused exceedance of design hazard in thousands of square kilometers. The most relevant effects of the sequence are, as expected, due to the mainshock, yet seismic actions larger than those enforced by the code for structural design are found also around the epicenters of the smaller magnitude events. At some locations, the succession of ground-shaking that has excited structures, provides insights on structural damage accumulation that has likely taken place; something that is not accounted for explicitly in modern seismic design. The envelopes developed are available as supplemental material.


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