Numerical analysis of seepage under weir foundation

Dissertant

Abu Rishah, Rafid Sadun Rashid

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Master

Degree Date

2008

English Abstract

In the present research GEO-SLOPE, SEEP / W finite element package is used to analyse seepage How through isotropic, pervious, saturated homogenous Or non homogenous soils underneath weir foundation and study the effect of seepage on the, foundation of weir.

This program depends on the finite element method, two dimensional model of quadrilateral finite element is used to solve such problems in this research The program GEO-SLOPE; SEEP / W has been verified by using problems which were solved by flownct method and its results are compared with die output of the program for die same conditions.

All different in results percents are less then10 %.

These results indicate acceptable agreement between these two methods, The first problem which has been analyzed in the present work is a weir structure with two sheet piles (one in upstream and the other in downstream side) which rest on non-homogeneous soil foundation (two different layers of sail)and calculating the quantity of seepage, uplift pressure head and exit gradient on different cases.

the cases are (a)variation in the permeability in one of the two layers of soil when the other is fixed ; (b)variation in the upstream sheet pile depth ; (c)variation in the downstream sheet pile depth ; (d)variation in thickness of the two layers while die total thickness of soil foundation is fixed.

A set of curves explaining the quantity of seepage, uplift pressure and exit gradient results from these cases has been obtained.

It has been found that the quantity of seepage and exit gradient increase with increasing the permeability value and thickness of soil layer.

However, using upstream sheet pile is useful to reduce the uplift pressure head underneath reduce the exit gradient.

These deductions are useful for studying the case study (Diyala weir), Diyala weir structure suffering from sucli engineering problems, that's why it was taken as a case study and it has been drawn and checked against piping and uplift pressure by using the program.

The effect of removing or defect one of the three sheet pile LOWS was studied and calculated to investigate the quantity of seepage, uplift pressure and cxit Gradient for those cases.

It has been found that the weir foundation and downstream floor problems cracks and displacement) are due to detect or corrosion of the sheet piles especially in upstream These problems are not happening when all parts of the Diyala weir structure arc fulfilling their functions.

Main Subjects

Civil Engineering

Topics

• Dams
• Mechanics
• Soil physics
• Soil mechanics
• Iraq
• Diyala

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305536