scholarly journals ANALYTICAL STUDY ON THE EFFECTS OF ADJACENT BUILDING ON DYNAMIC SOIL STRUCTURE INTERACTION OF PILE FOUNDATION AND PILED RAFT FOUNDATION

2006 ◽  
Vol 71 (606) ◽  
pp. 147-154 ◽  
Author(s):  
Xuezhang WEN ◽  
Nobuo FUKUWA
Keyword(s):  
Pile Foundation ◽  
Soil Structure ◽  
Analytical Study ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Adjacent Building

scholarly journals Effect of Dynamic Soil-Structure Interaction on Raft of Piled Raft Foundation of Chimneys

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
B. R. Jayalekshmi ◽  
S. V. Jisha ◽  
R. Shivashankar ◽  
S. Soorya Narayana
Keyword(s):  
Soil Properties ◽  
Ground Motion ◽  
Soil Structure ◽  
Seismic Analysis ◽  
Direct Method ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation

This paper presents numerical analysis of soil-structure-interaction (SSI) of tall reinforced concrete chimneys with piled raft foundation subjected to El Centro ground motion (1940) using finite element method. Seismic analysis in time domain was performed on the basis of direct method of SSI on the three-dimensional SSI system. The chimney, foundation, and soil were assumed to be linearly elastic in the analysis. The stress resultants and settlement of raft of piled raft foundation were evaluated under different soil properties and different geometrical features of raft and chimney. Soil properties were selected based on the shear wave velocity corresponding to sand in the loose to dense range. Chimneys with different elevations of 100 m, 200 m, and 400 m were taken with a ratio of height to base diameter of chimney of 17. Raft of different thickness was considered to evaluate the effect of stiffness of foundation. Results were analysed to assess the significance of characteristic of the ground motion. It is found that the response in the raft depends on the different parameters of chimney, foundation, and soil. It is also found that the higher modes of SSI system are significant in determining the response in the raft.

Influence of Foundation Type on Seismic Performance of Buildings Considering Soil–Structure Interaction

2016 ◽  
Vol 16 (08) ◽  
pp. 1550043 ◽  
Author(s):  
Aslan S. Hokmabadi ◽  
Behzad Fatahi
Keyword(s):  
Seismic Response ◽  
Pile Foundation ◽  
Soil Structure ◽  
Soft Soil ◽  
Shallow Foundation ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Raft Foundation ◽  
Different Types

In selecting the type of foundation best suited for mid-rise buildings in high risk seismic zones, design engineers may consider that a shallow foundation, a pile foundation, or a pile-raft foundation can best carry the static and dynamic loads. However, different types of foundations behave differently during earthquakes, depending on the soil–structure interaction (SSI) where the properties of the in situ soil and type of foundation change the dynamic characteristics (natural frequency and damping) of the soil–foundation–structure system. In order to investigate the different characteristics of SSI and its influence on the seismic response of building frames, a 3D numerical model of a 15-storey full-scale (prototype) structure was simulated with four different types of foundations: (i) A fixed-based structure that excludes the SSI, (ii) a structure supported by a shallow foundation, (iii) a structure supported by a pile-raft foundation in soft soil and (iv) a structure supported by a floating (frictional) pile foundation in soft soil. Finite difference analyzes with FLAC3D were then conducted using real earthquake records that incorporated material (soil and superstructure) and geometric (uplifting, gapping and [Formula: see text] effects) nonlinearities. The 3D numerical modeling procedure had previously been verified against experimental shaking table tests conducted by the authors. The results are then presented and compared in terms of soil amplification, shear force distribution and rocking of the superstructure, including its lateral deformation and drift. The results showed that the type of foundation is a major contributor to the seismic response of buildings with SSI and should therefore be given careful consideration in order to ensure a safe and cost effective design.

ANALYTICAL STUDY OF PILED-RAFT FOUNDATIONS CONSIDERING PLAN GEOMETRY AND NONLINEAR BEHAVIOR OF GROUND

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Haruyuki Yamamoto ◽  
He Huang
Keyword(s):  
Pile Foundation ◽  
Analytical Study ◽  
Nonlinear Behavior ◽  
Theory Of Elasticity ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Raft Foundations

The piled-raft foundation transfers loading to the ground by the raft and the piles together. It was proposed in the 1970s and is widely used for controlling settlement. Simplified estimate equations are used for the primary design. Equations by Randolph can presume the settlement stiffness of the piled-raft foundation and the loading share ratio from the settlement stiffness of raft and pile foundation. Raft foundations not only have regular shapes as squares, they also have some particular shape like triangular or L-plan. Therefore, different shape plans are discussed in this paper to verify the applicability of these equations. Also, these equations are proposed based on a theory of elasticity. However, the ground has nonlinear behavior even under small loading levels, so estimating the applicability of these equations when the ground behaves nonlinearly is necessary.

scholarly journals Soil-Structure Interaction Analysis of Tall Reinforced Concrete Chimney with Piled Raft and Annular Raft under Along-Wind Load

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
B. R. Jayalekshmi ◽  
S. V. Jisha ◽  
R. Shivashankar
Keyword(s):  
Reinforced Concrete ◽  
Soil Structure ◽  
Wind Load ◽  
Soil Structure Interaction ◽  
Elastic Behaviour ◽  
Bending Moments ◽  
Structure Interaction ◽  
Piled Raft ◽  
Raft Foundation ◽  
Annular Raft

A three-dimensional (3D) soil-structure interaction (SSI) analysis of 300 m high reinforced concrete chimneys having piled annular raft and annular raft foundations subjected to along-wind load is carried out in the present study. To understand the significance of SSI, four types of soils were considered based on their flexibility. The effect of stiffness of the raft was evaluated using three different ratios of external diameter to thickness of the annular raft. The along-wind load was computed according to IS:4998 (Part 1)-1992. The integrated chimney-foundation-soil system was analysed by commercial finite element (FE) software ANSYS, based on direct method of SSI assuming linear elastic behaviour. FE analyses were carried out for two cases of SSI (I) chimney with annular raft foundation and (II) chimney with piled raft foundation. The responses in chimney such as tip deflection, bending moments, and base moment and responses in raft such as bending moments and settlements were evaluated for both cases and compared to that obtained from the conventional method of analysis. It is found that the responses in chimney and raft depend on the flexibility of the underlying soil and thickness of the raft.

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