Application of random set method in a deep excavation: based on a case study in Tehran cemented alluvium

In this paper, the construction and performance of a deep metro station excavation is presented. Top-down construction method has to be used in this deep excavation as it is located under the high speed railway, and the potential deformations of both structures and railway subgrade are extremely large. In order to reduce the deformations and ensure safety during the construction, several design and construction measures were taken including the thickening diaphragm walls, two additional temporary concrete struts, large area of soil improvement, and dense drilled piles. Additionally, a novel excavation method is used to improve construction efficiency. Field performance data were collected (i.e., lateral wall deflections, vertical displacements of diaphragm wall, middle slabs and railway subgrade, and support system loads). Results are comprehensively analyzed and show that the deformations of structures and railway subgrade are controlled within limited range.

Ground motion intensity measures ( IMs) are an important basis of structural seismic design. Extensive research has been conducted on the selection of IMs for building structures with fundamental periods shorter than 6 s. However, minimal work has been performed for super high-rise buildings whose fundamental periods are much longer than 6 s. To fill the gap in this research area, this paper aims to develop a simplified analytical model for super high-rise buildings based on the flexural-shear coupled beam model. The variation in correlation and dispersion between different IMs is evaluated and the structural seismic response demand measures ( DMs) are analyzed for different structural fundamental periods. Subsequently, rational IMs for the seismic design of super high-rise buildings are suggested. In addition, the influence of different flexural and shear stiffness ratios, α 0 , on the selection of an IM for super high-rise buildings is also discussed. Finally, a series of incremental dynamic analyses (IDA) of the Shanghai Tower, with a total height of approximately 632 m, is performed to verify the rationality of using different IMs for super high-rise buildings. The numerical results indicate that with a minimum dispersion, the peak ground velocity (PGV) has a better correlation to the story drift ratio than any other IMs. While considering structural nonlinearity, PGV still yields the minimum coefficient of variation in the collapse analysis of the actual super high-rise building. It is therefore recommended that PGV be used as an IM for the seismic design of super high-rise buildings.

Modular design refers to a design approach whereby customized modules or components are assembled to form the layout plan of a building. Previous researches have attempted to optimize the layout plan design of low-rise houses for maximizing the natural daylighting, ventilation performance, and energy efficiency. Engineers have also studied the modular design of high-rise residential buildings to meet site constraints and to optimize site development potentials. However, the previous studies on modular building design were based on empirical trial-and-error approaches, efficient methods for identifying the optimal combination of different modules and components were still lacking in literature. Therefore, this study attempts to develop an innovative approach for optimizing the modular design of high-rise residential buildings, with the aim of maximizing the building energy performance while fulfilling the site constraints and design code requirements. The design optimization problem, including the design variables and objective functions, is properly formulated to guarantee the quality of final optimized deign. Provided a set of well-defined modules and components, evolutionary genetic algorithm (GA) is then utilized for the wide-ranging exploration of the building layout plans, taking into consideration the site conditions and building design requirements. A computer program is developed, coupling the GA optimization and energy modeling, to systematically evaluate the candidate layout plans. The energy simulation results are subsequently used to guide the GA towards finding the optimal design solution. The proposed optimization method is utilized to generate the optimal layout design for a 40-story high-rise residential building, using a set of pre-defined modular flat units. The optimal design maximizes the use of natural ventilation and daylighting to save 30-40% of the energy consumption without compromising the site constraints and design requirements. The findings of this study serve as the decision support basis to enhance modular design of high-rise residential buildings (such as energy conservation in this study), thereby improving the sustainability and cost-effectiveness of the built environment.

Stability problems in a deep excavation in clay: Aas, G Proc International Conference on Case Histories in Geotechnical Engineering, Rolla, Missouri, 6–11 May 1984V1, P315–323. Publ St Louis: Geotechnical Engineering, 1984

This study presents a procedure applied to design problems for lateral loaded piles. Calculations for a rigid concrete pile in non-cohesive soil are conducted with the aim of estimating the allowable horizontal force using the methods of Broms and Petrasovit. Random sets are applied to represent the uncertainties of soil parameters, including the internal friction angle and unit weight. Random variables are described using log-normal and beta distributions. Random set theory is utilised to represent variability in the form of probability boxes, possibility distributions, cumulative distribution functions, or intervals. Based on the assumed distributions of the subsoil, the lower and upper bounds for the precise probability of fulfilment of the limit state function of a laterally loaded pile are estimated. The reliability calculation procedure is implemented using the R package (R Studio v2024.12.1+563), and the limit forces and reliability indicators calculated using the two considered methods are compared. The presented procedure serves as an example of the use of a probabilistic approach for the assessment of the capacity of a laterally loaded pile, using a setup for the task involving set-based data and discrete probability distributions.

Modeling the surface element and support system in deep excavation pits and investigating the deformation mechanism is an important issue. In this study, alternative solution methods for an anchored bored pile model are compared and discussed, and it is aimed to contribute to the studies to be carried out in the deep excavation area. A numerical analysis of retaining wall design is examined in the case of the Sivas cultural center building's deep excavation using Plaxis 2D and GGU-Retain software. Measured field data and simulated results are discussed. As a result, the bending moment and lateral deformation reach a maximum when the foundation pit is excavated to the bottom. It can be said that the lateral deformation value found with Plaxis 2D is within the allowable limits, closer to the field data, and provides sufficient quality. The research results will provide theoretical and practical knowledge for designing and constructing similar deep excavation pits for the optimal strategy.

The emergence of expert systems, interactive computer programs that incorporate the knowledge and judgment of experts in appropriate domains, promises to extend significantly the use of the computer in the design of high-rise buildings. In current design practice, the use of computers is limited to areas in which algorithmic solutions are available, such as analysis of structural systems and proportioning of components. Expert systems provide a means for using the computer in the solution of problems that have resisted being formalized as algorithms. This paper examines the use of expert systems in the preliminary design of high rise buildings through a discussion of the prototype expert system HI-RISE. The nature of expert systems is described, followed by a discussion of HI-RISE. Using HI-RISE as a starting point, potential expert systems in building design are described and the impact of such systems on the building design process are discussed.

With ever increasing land prices, design and construction of high-rise buildings are becoming very common. There is a trend among design Engineers to resort to 3D Finite Element Analysis (FEA) during the design of such high rise buildings. This is due to the fact that challenging architectural concepts, when combined with inherent complexities and scale of such projects, require the need of complex structural systems and components such as outriggers, transfer plates, etc. However incorrect modeling input and assumptions could lead to a situation where predictions made using such models may differ greatly from the actual behaviour. In this paper, the importance of accuracy in modeling FEA of high rise buildings is demonstrated through the use of a case study of a 34 storey hotel building with outriggers. The impact of modeling accuracy and assumptions on the predicted performance of the outrigger is also evaluated.

The principle cause of this study is to layout a whole building relaxation on a single column. The rapid increase in population and scarcity of land tends to the development of construction technology and high- rise commercial structures. The building plays a vital role in improving various activities in the late world. The Aim of present study “Analysis and design of high rise building by staad pro is to define proper technique for creating Geometry, cross sections for column and beam etc, developing specification and supports conditions, types of Loads and load combinations. In this study a 30- storey high rise structure is analyzed for seismic and wind load combination using staad pro and comparison is drawn. Currently, there are four mosques on Java Island recognized as Saka Tunggal Mosques, which employ a single wooden column as the main column, placed at the center of the prayer hall to support the roof. This unique structural system, when compared to the traditional four-column system, is remarkable even if its style is exceptional for mosques on Java Island. This study aims to provide scientific data and promote the local government's understanding about the importance of the Saka Tunggal Mosques by focusing on the one in Banyumas, which is placed at a cultural heritage site, founded in 1871. The rapid increase in population and scarcity of land tends to the development of construction technology and high-rise commercial structures. Building plays a vital role for improving the various activities. In the late world, prompt to action of peoples from one place to another is of great extent mainly for earnings. In building more facilities like financing section, computer section, administration section, design section and drawing section are provided. The aim of the project is to analyse and design of multi-storey building resting on the single column by using different code provisions. A lay out plan of the proposed building is drawn by using AUTO CADD. The structure consists of ground floor plus five floors, each floor having the one house. Staircase must be provided separately. The planning is done as per Indian standard code provisions. The building frames are analyzed using the various text books. Using this so many standard books analysis of bending moment, shear force, deflection, end moments and foundation reactions are calculated. Detailed structural drawings for critical and typical R.C.C. members are also drawn. Recent studies regarding progressive collapse resistance of buildings considered only single critical column removal scenario. However, limited investigations have been conducted so far to assess multi-column removal scenarios. Hence this study is made to compare progressive collapse resistance of a multi-story building under both single and multi-column removal scenarios. An eight-storey reinforced concrete building was analyzed by using linear static analysis procedure and DCR values of the members are calculated to investigate the potential of progressive collapse as per GSA guideline.

This paper presents a case history in Giza, Egypt in which the settlements of existing structures founded on shallow and deep foundations surrounding a deep excavation retained by strutted diaphragm walls were monitored. The presented case history comprised inclusive settlement monitoring during the different stages of construction including diaphragm wall trenching and the stages of excavation to the foundation level. The measured settlements were back-analyzed using two and three dimensional numerical models to evaluate the different deformation patterns associated with wall and pit excavation stages. The analyses showed that foundation settlements, during the different stages of deep excavations including the diaphragm wall trenching, are substantially influenced by the foundation type and depth and its relation to the depth of excavation.

With the development of construction technology and material, more and more super high-rise buildings will be constructed in the future. In a specific metropolitan area, super high-rise building with various cross-section and high side ratio have to been designed and constructed due to the size limitation of construction site. This kind of building is also very prone to wind excitations. In this research, wind tunnel tests for a practical case of this kind of building with surrounding buildings were carried out in atmospheric boundary wind tunnel. Equivalent static wind loads (ESWLs), wind-induced responses and wind load distribution on the building were analyzed. In particular, the base overturning moment along the axis with weak lateral stiffness were investigated for bearing capacity limit state design of the building. The results demonstrate that the maximum value of wind-induced base overturning moments and acceleration responses appears at 60° or 330° wind directions instead of the orthogonal wind direction, and the aerodynamic interference of surrounding buildings affects the wind pressure distribution on facades of the building. These results and conclusion may be helpful to wind-resistant design of super high-rise buildings with high side ratio.

The article examines the design of bioclimatic high-rise buildings, taking into account the formation of the mesoclimate and sustainable urban environment. The current pace of urban development makes it possible to talk about the formation of an urban ecosystem, which is significantly different in its characteristics from a natural ecosystem. Therefore, the task of bioclimatic design is not to solve individual design problems, for example, those related to energy saving, but to create a holistic ecological environment for urban development with the possibility of harmonious coexistence between man and nature. In the course of the study, the main natural factors (lithosphere, hydrosphere, biosphere, atmosphere) that affect the bioclimate of the area and the design of bioclimatic high-rise buildings were identified. It has been determined that bioclimatic design solutions can have significant variability, which is associated with construction conditions, design tasks, and technology development. Therefore, to generalize them, the following indicators for assessing the development of bioclimatic design solutions were identified: counteraction to climate change; sustainable city development policy; nature and biodiversity; waste; energy efficiency. Based on the analysis of the reconstruction of Marina City towers, which has a bioclimatic orientation of design solutions at the meso-level (for Chicago, USA), the relationship between the mesoclimate and bioclimatic design has been investigated, which makes it possible to find optimal solutions to improve the quality of the human living environment in the city.

In this paper, an optimal design process for high-rise building structures is presented based on cost-effectiveness criterion. Then, an optimal design of a complex high-rise building based on cost-effectiveness criterion is carried out by using the design process. A minimum life cycle cost and corresponding elastic inter story drift considering initial cost and damage cost as two separate objective functions are obtained by using genetic algorithm. Finally, fitting curves of life cycle cost, initial cost, damage cost and corresponding performance indexes are interpolated by using one-dimensional linear interpolation considering elastic inter story drift ratio as control performance indexes. And lots of life cycle cost designs and corresponding performance indexes of the separated objective function are given. The results show that the optimal design process is practical and optimal results are diverse, and can be chosen flexibly by owners.

The slopes of open-pit mines are often at risk of failure. To identify this hazard, stability analyses are performed. An important element of these stability analyses is the reliable selection of input parameter values for the calculations. This selection is difficult because the slopes of the open pit are disturbed by mining activities. In such conditions, rheological processes, intensified by weathering, develop in open-pit slopes. This study is aimed at setting the strength parameters for the stability analysis of open-pit slopes with a developed slide process, using the random set method. The study was performed on the example of the open pit of the Bełchatów lignite mine, central Poland. A four-stage methodology, according to the random set method, was proposed. The methodology covered the following: site investigation, sensitivity analyses, shear strength reduction (SSR) analyses using numerical calculations, and probability analyses of the factor of safety (FoS) calculation results. The setting of the input parameters took into account the peak and residual strength parameters for each lithological unit in the physical model of the open-pit slope. Samples for laboratory tests were taken from the cores of nine test boreholes. The sensitivity analysis included all peak and residual strength parameters for each lithological unit in the body. As a result of the sensitivity analysis, specific strength parameters were adopted that would have a great impact upon the results of the calculations. Selected sets of parameter values were then used for the FoS calculations. The resultant FoS values revealed the probable slide planes. The positions of the slide planes were consistent with the interpreted slide surfaces based on the control boreholes and terrain observations. Knowledge of the slide planes positions and the values of the strength parameters enabled the designing of a securing approach for this landslide, and the taking of preventive measures to reduce this risk.

Community Perspectives on Air Pollution and its Related Health Risks: A Case Study of Tehran (2012-2013)