Foundation Design

RINGWALL FOUNDATION DESIGN

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Document Control No.

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AAK 099 CE 40 0099 A

Ring Wall Foundation for Tank Revision: A

Revision History

REV DATE ISSUE PURPOSE ORIGINATOR CHECKED BY:

APPROVED BY:

A 17-Aug-10 ISSUED FOR IDC AZ PG MC/JB

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Holds:

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Table of Contents

1.0 INTRODUCTION................................................................................................................. 41.1 EXECUTIVE SUMMARY.....................................................................................................41.2 PROJECT SCOPE:............................................................................................................. 42.0 IN-PLACE ANALYSIS..........................................................................................................52.1 BASIS OF DESIGN............................................................................................................. 52.2 PARAMETERS AND CRITERIA..........................................................................................52.2.1 DESIGN THEORY AND ASSUMPTIONS...........................................................................52.2.2 MATERIALS........................................................................................................................ 62.2.3 SOFTWARES......................................................................................................................63.0 MODEL DESCRIPTION...................................................................................................... 73.1 STAAD PRO MODEL..........................................................................................................73.2 DIMENSIONAL MODEL......................................................................................................83.2.1 BOUNDARY CONDITIONS.................................................................................................93.2.2 MODEL UNITS....................................................................................................................93.2.3 CO-ORDINATE SYSTEMS.................................................................................................93.3 LOADING CALCULATIONS..............................................................................................103.4 STABIILITY ANALYSIS.....................................................................................................113.5 LOAD COMBINATIONS....................................................................................................134.0 ANALYSIS RESULTS........................................................................................................144.1 HOOP STRESSES IN RING WALL...................................................................................144.2 NODE DISPLACEMENT SUMMARY FOR RING WALL FOUNDATION BASE................155.0 REINFORCEMENT CALCULATION FOR RING WALL AND BASE FOUNDATION........16

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1.0 INTRODUCTION

1.1 EXECUTIVE SUMMARY

The report presents the structural analysis and design of the Ring Wall Foundation for Diesel Storage. The analysis was based on the Design codes and Specifications listed in this report.

A three-dimensional (3-D) model of the Ring Wall Foundation was analyzed with STAAD Foundation Advanced software and was analyzed for strength, serviceability and stability criteria under the applied shell load, operating and Test load. The effect of wind load has not been considered in this analysis.

The results show that the proposed structural members and foundation were suitable for the purpose for which they were designed.

1.2 PROJECT SCOPE:

The structural scope for the project is to design the ring wall foundation to withstand the anticipated hoop stresses, tank shell load and operating loads that would act on it, and provide adequately sized foundation to support these loads during the design life of the structure.

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2.0 IN-PLACE ANALYSIS

2.1 BASIS OF DESIGN

Codes, Standards and References:

The R.C.C Structure analysis has been designed in accordance with the latest editions of and related amendments of the following:

AMERICAN CONCRETE INSTITUTE (ACI - 318)

PIP STE03020: Guidelines for Tank Foundation Designs

BS6399-1: 1997. Code of Practice for Dead and Imposed Loads. Part 1

BS6399-2: 1997. Code of Practice for Wind Loads. Part 2

BS6399-3: 1997. Code of Practice for Imposed Roof Loads. Part 3

BS8110-1: 1997. Structural Use of Concrete. Part 1

BS 8004: 1986. Code of Practice for Foundation

2.2 PARAMETERS AND CRITERIA

2.2.1 DESIGN THEORY AND ASSUMPTIONS All R.C.C structural members shall be in accordance with ACI

Foundations shall be founded on either undisturbed soil or compacted fill and the depth shall be based on the result of soil test and the required lateral resistance but in no case be less than 1200 mm below the existing or finished grade surface (finished ground level),

The assumed bearing capacity of the soil shall be taken as 286 KN/m2.

The concrete grade shall be C25 for sub Structure and C30 Super Structure and the reinforcement shall be Fy = 60 Ksi (415 MPa )

The minimum concrete cover shall be as follows

Columns 1.25 inches 33 mm

Beams 2.0 inches 50 mm

Slabs 0.75 inches 20 mm

Foundation 3 inches 75 mm

The loads used for this footing design shall be service load reactions obtained from an elastic analysis of the superstructure. The weight of the footing and soil overburden shall be combined with the service loads.

Factor Of Safety against Sliding is 1.5 while F.O.S against overturning shall be 1.5

Wind velocity shall be taken as 145 kilometer/hour (40.3 m/s)

2.2.2 MATERIALS

Density of concrete shall be 23.6 KN/m3 (150 psi)

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2.2.3 SOFTWARES

- Structural Analysis Software – STAAD Pro

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3.0 MODEL DESCRIPTION

3.1 STAAD PRO MODEL

STAAD Pro was used to create a 3D model of the proposed Ring Wall foundation for fire water storage tank, based on tank requirements provided by Tank and Mechanical Department.

Figure 3.1: STAAD 3D Model

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3.2 DIMENSIONAL MODEL

Figure 3.2: STAAD Dimensional Model

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3.2.1 BOUNDARY CONDITIONS

Plate Mat condition was adopted for the model to simulate ring wall base foundation, with Modulus of Sub grade Reaction of 18000 KN/m2/m.

3.2.2 MODEL UNITS

Standard S.I units were adopted in the STAAD pro model.

3.2.3 CO-ORDINATE SYSTEMS

The global coordinate system adopted in the model is the conventional Cartesian co-ordinate system (X, Y, and Z) which follows the orthogonal left hand rule where the Y is upwards vertical positive, X is horizontal right positive and Z is perpendicular to X on the same plane. Z is positive pointing back.

Y Y

X Z

Z X (a) (b)

Figure 1.3: (a) Global Co-ordinate System, (b) Local Co-ordinate System

The local coordinate system is also similar except that the X and Z axes interchange orientations. While general modeling and loading were based on the global coordinate system, analysis result member stresses are based on the local co-ordinate system.

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3.3 LOADING CALCULATIONS

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3.4 STABIILITY ANALYSIS

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3.5 LOAD COMBINATIONS

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4.0 ANALYSIS RESULTS

4.1 HOOP STRESSES IN RING WALL

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4.2 NODE DISPLACEMENT SUMMARY FOR RING WALL FOUNDATION BASE

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5.0 REINFORCEMENT CALCULATION FOR RING WALL AND BASE FOUNDATION

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Foundation Design