by

8 Balandra Place KAREELA NSW 2232 Australia Phone +61 2 9589 1135 Email sgikas@bigpond.net.au Website www.pttanksoftware.com DESIGN OF CIRCULAR LIQUID

RETAINING STRUCTURES

A Comprehensive Computer Package for the Analysis and Design of

Prestressed Tanks (Precast or Insitu)

PTtank analyses and designs a tank, generating an A3 drawing in less than 5 minutes

PTtank has been written and developed by a practicing structural engineer

specializing in Post-Tensioned structures

PTtank is a Windows standalone program that analyses and designs circular, liquid retaining structures (Tanks). The Tank is prestressed in the horizontal direction, but can be stressed or reinforced only, in the vertical direction PTtank Generates a Quantities report together with an A3 drawing, complete with details for tender pricing and issue.

• Tank Size: Diameter, Wall and Water Heights THE INPUT

• Construction Wall Type: Precast or Insitu • Tank Wall Fixity

o Top can be Free or Pinned o Bottom can be Free, Pinned or Rubber

• Hoop Tendon Details: Stressing Arrangement o Two, Four or Six Stressing Points

• Hoop Tendon Anchor Type o Buttress (Pilaster) or Pocket (Z-Type)

• For Precast Walls, the Panel

Constraints o Maximum Panel

Weight and Width o Wet Joint Width

PTtank evaluates the Tendons (Hoops) Losses, and determines the number of Tendons required, to balance the applied loads. It accurately defines the location of each tendon up the wall.

THE HORIZONTAL (HOOPS) TENDONS

The Tendons (Hoops) Stressing Sequence generally controls the design of the wall vertically. PTtank uses the most efficient and economic sequence (‘Odds-Up-Evens-Down’), to stress the Hoops. PTtank graphically animates the sequence. This helps user understand this complex operation.

PTtank generates all required Load Cases. These are: TANK LOADING CASES

• Gravity: Self Weight, Additional Dead, and Live Loads • Hydrostatic: Overflow and Service

• Temperature – Four Cases

• Moisture Variation: Swelling and Shrinkage

TANK LOADING CASES—Continued)

• Earth (Embedded Tanks Only) • Earthquake Loading on Water • Earthquake on Soil (Embedded Tanks Only)

PTtank Analyses each Load Case individually, and the results are Tabulated and Plotted.

TANK LOADING CASES and ANALYSIS RESULTS

PTtank generates all factored Load Combinations (40 off), required for the design The Controlling Combinations (Vertical and Horizontal), are displayed in the Analysis Results Summary

COMBINATION OF LOAD CASES

PTtank performs a Cracked Section Design for all load combinations, for each node, in both directions. (That is 1,680 checks for a 20 node Tank). The Controlling Conditions are displayed in the Design Results Summary.

DESIGN of WALL

User can selectively view, individual Combinations and their Analysis and Design Results

PTtank analyses and designs the Ring Footing Beam, to carry all the wall generated actions

RING FOOTING BEAM

PTtank analyses and designs the Tank Slab as a Prestressed Slab-On-Grade to carry all Tank generated actions

TANK SLAB

Generated Tender Drawing

Tank Input Details

Stressing Arrangement Anchor Types

Panel Constraints

Horizontal Tendons (Hoops) – Number Required

Horizontal Tendons (Hoops) Losses

Gravity Loads Hydrostatic Loads

Temperature Loads

Moisture Variation Earth Loading

Earthquake on Water

Earthquake on Soil (Embedded Tanks)

Plots of Vertical Deflection, Moment, Shear & Axial Forces

Plots of Horizontal Moment And Hoop Tensile Force

Tabulation of Analysis Results

Analysis Results Summary

Design Results Summary

Individual Load Combination – Analysis and Design Results

Ring Footing Design

Tank Slab Design

PTtank Synopsis