scholarly journals Effect of Lateral Loads and Soil Structure Interface on Structural Performance of RCC Chimney

Chimneys are distinguished requirements for Power generation and other Manufacturing areas which are vital to be constructed vertically to discharge combustion gases and chemical waste gases to the environment. Due to the hasty growth of mechanization and escalating the requirement to control of Air pollution, the construction of tall Chimneys becomes a regular structure in contemporary circumstances. Tall chimney shells generally designed to resist vertical and lateral loads especially due to the effect of Wind and Earthquake. RCC Chimney shell will transfer these vertical and lateral loads to its foundation system. Soil Structure Interaction (SSI) is the response of soil which impacts the behavior of the structure or behavior of the structure which affects on response of soil. Soil Structure Interaction is essential for tall structures which especially resting on soft soil strata. This review work presents a widespread appraisal of the research presented in the area of RCC chimney and communicates most recent enlightenments and improvements happened in the analysis and design. This paper makes an attempt on focusing the modeling features of RCC chimneys which contains analysis, design aspects and several case studies, with the help of various software programs with the effects of lateral loads and soil structure interaction. The present review paper also corresponds to a complete anthology of the research accomplished on RCC chimney and will gives rationalized technical information for the researchers.

Author(s):  
Abdolghafour Khademalrasoul ◽  
Arash Shirmohammadi ◽  
Mohammad Siroos Pakbaz ◽  
Mojtaba Labibzadeh

2020 ◽  
Vol 10 (23) ◽  
pp. 8357
Author(s):  
Ibrahim Oz ◽  
Sevket Murat Senel ◽  
Mehmet Palanci ◽  
Ali Kalkan

Reconnaissance studies performed after destructive earthquakes have shown that seismic performance of existing buildings, especially constructed on weak soils, is significantly low. This situation implies the negative effects of soil-structure interaction on the seismic performance of buildings. In order to investigate these effects, 40 existing buildings from Turkey were selected and nonlinear models were constructed by considering fixed-base and stiff, moderate and soft soil conditions. Buildings designed before and after Turkish Earthquake code of 1998 were grouped as old and new buildings, respectively. Different soil conditions classified according to shear wave velocities were reflected by using substructure method. Inelastic deformation demands were obtained by using nonlinear time history analysis and 20 real acceleration records selected from major earthquakes were used. The results have shown that soil-structure interaction, especially in soft soil cases, significantly affects the seismic response of old buildings. The most significant increase in drift demands occurred in first stories and the results corresponding to fixed-base, stiff and moderate cases are closer to each other with respect to soft soil cases. Distribution of results has indicated that effect of soil-structure interaction on the seismic performance of new buildings is limited with respect to old buildings.


Author(s):  
Steffen Leppla ◽  
Arnoldas Norkus

Roads and road infrastructure systems are designed to satisfy ultimate and serviceability conditions under long-term actions caused by transport loadings and environmental effects. Selected design solutions must be safe and rational in terms of construction and maintenance costs. In cases when weak or soft soil layers of natural soil profiles are shallow and/or the traffic loads are very large, the Combined Pile-Raft Foundation (CPRF) is the economical road and railway structure design solution. Application of CPRF is cheaper geotechnical solution comparing with soil change or usual piled foundation alternatives. The development of this system is based on the analysis of relevant mechanical properties of soil layers and the evaluation of the soil-structure interaction. The soil-structure interaction is of highest importance allowing proper evaluation of load bearing resistance and deformation transmitted by raft and piles to soil layers. The soil and foundation system usually is subjected by loadings, resulting elastic-plastic resistance range. Therefore, relevant nonlinear physical laws due to the stress levels are used. The paper purpose is summarizing the experience of application of Combined Pile-Raft Foundations used in road and railway construction and bridge engineering.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Karmegam Rajkumar ◽  
Ramanathan Ayothiraman ◽  
Vasant A. Matsagar

In this paper, the influence of soil-structure interaction (SSI) on a torsionally coupled turbo-generator (TG) machine foundation is studied under earthquake ground motions. The beneficial effects of base isolators in the TG foundation under earthquake ground motions are also studied duly, considering the effects of SSI. A typical TG foundation is analyzed using a three-dimensional finite element (FE) model. Two superstructure eccentricity ratios are considered to represent the torsional coupling. Soft soil properties are considered to study the effects of SSI. This research concludes that the effects of torsional coupling alter the natural frequencies, if ignored, could lead to unsafe design. The deck accelerations and displacements are increased with an increase in superstructure eccentricity. On the other hand, the deck accelerations and displacements are greatly reduced with the help of base isolators, thus confirming the beneficial use of base isolators in machine foundations to protect the sensitive equipment from the strong earthquake ground motions. However, the effects of SSI reduce the natural frequencies of the TG foundation resting on soft soil conditions and activate the higher mode participation, resulting in amplifying the response.


Author(s):  
Ali Kaveh ◽  
Shaylin Rezazadeh Ardebili

The present paper focuses on the optimum design of tuned mass damper (TMD) as a device for control of the structures. The optimum free vibration parameters such as period and damping ratio depend on the soil condition. For this reason, the seven meta-heuristic algorithms namely colliding bodies optimization (CBO), enhanced colliding bodies optimization (ECBO), water strider algorithm (WSA), dynamic water strider algorithm (DWSA), ray optimization (RO) algorithm, teaching-learning-based optimization (TLBO) algorithm and plasma generation optimization (PGO) are used to find the TMD parameters considering soil-structure interaction (SSI) effects. These optimization methods are applied to a benchmark 40-story structure. For comparison, the obtained results of these algorithms are compared. The capability and robustness of the algorithms are investigated through the benchmark problem. The results are shown that the soil type affects the optimum values of the TMD parameters, especially for the soft soil. To evaluate the performance of the obtained parameters in both the frequency and time domains, time history displacement and acceleration transfer function of the top story of the structure are calculated for the model with and without considering the SSI effects.


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