research centers


Search results: Found 2

Listing 1 - 2 of 2
Sort by

Article
Water Budget and Performances of Three Rainfall – Runoff models for Upper Adhaim River Basin

Authors: Ayad S. Mustafa --- Thair Sh. Khayyun
Journal: Iraqi Journal of Civil Engineering المجلة العراقية للهندسة المدنية ISSN: 19927428 Year: 2009 Volume: 6 Issue: 1 Pages: 12-30
Publisher: University of Anbar جامعة الانبار

Loading...
Loading...
Abstract

ABSTRACT
An applied hydrological models were performed to model the rainfall-runoff relationship for Upper Adhaim River Basin. Three lumped integral models (hydrologic models) based upon the concept of the unit hydrograph were applied to analyze the rainfall-runoff relationship on a daily basis. These models are: the Simple Linear Model (SLM), the Linear Variable Gain Factor Model (LVGFM), and the Non-Linear Model (NLM). Five performance evaluation criteria have been used in this study. The application results of the (SLM) model showed a weak rainfall-runoff relationship. It was demonstrated that the linear assumption is valid only for the first four antecedent days. A considerable non-linear rainfall-runoff relationship was clearly observed from the results of (LVGFM) and the (NLM) models. Both models were satisfactorily identified at system memory of (17) antecedent days. However, the (LVGFM) was slightly superior to the (NLM). The (LVGFM) identified at system memory of seventeen antecedent days was used to simulate runoff flows. The simulation results show an acceptable applicability for the (LVGFM) in terms of simulating runoff events in time of its occurrence and volumetric fitness. The water budget for Upper Adhaim River Basin showed that an average of 73.4% from annual rainfall was evapotranspired, 8.0% was infiltrated and 18.6% was observed as direct runoff.

استخدمت ثلاثة نماذج هيدرولوجية لنمذجة وتحليل العلاقة اليومية بين الامطار والسيح السطحي لحوض نهر،(SLM) اعالي العظيم التي تعتمد على مبدأ الهيدروغراف القياسي. ان النماذج المستخدمة هي: النموذج الخطي البسيطاظهرت الدراسة بعد استخدام خمسة .(NLM) والنموذج الغير خطي (LVGFM) نموذج عامل المكسب للمتغير الخطياظهر علاقة ضعيفة بين المطر والسيح الخطي. وان الفرضيات الخطية (SLM) معايير لتقييم كفاءة النماذج بان نموذجصحيحة فقط للايام السابقة الاربعةالاولى. ان نتائج العلاقة الغير خطية بين المطر والسيح السطحي كبيرة وتلاحظ بشكل( قد حققا نتائج مقبولة عند ( 17 (NLM) و (LVGFM) ان كلا النموذجين .(NLM) و (LVGFM) واضح لنماذجوعلى ،(NLM) قد حقق نتائج افضل بعض الشيء مقارنة بنموذج (LVGFM) يوم سابقاً وعلى ايه حال فان نموذجللتنبؤ بالجريان السيح السطحي. اظهرت نتائج الدراسة التقارب المقبول (LVGFM) هذا الاساس فقد استخدم نموذجبين السيح السطحي الحقلي والنظري من حيث الوقت والحجم، كما خلصت دراسة الموازنة المائية لحوض نهر اعاليالعظيم بان 73.4 % من المطر السنوي يكون على شكل تبخر ونتح و 8.0 % على شكل ارتشاح وان 18.6 % يقاس علىشكل سيح سطحي مباشر.

Keywords


Article
Stability Analysis of an Earth Dam Using GEO-SLOPE Model under Different Soil Conditions

Authors: Usama R. Mishal --- Thair Sh. Khayyun
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 5 Part (A) Engineering Pages: 523-532
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Numerical models are used to check the stability of earth dams and to simulate the effects of all the parameters, which affect its safety. The physical properties of the materials used in the construction of an earth dam are one of these important parameters. The finite element analysis software used for numerical modeling in this study is GeoStudio 2007(SEEP/W and SLOPE/W). The total number of finite elements used to simulate the standard model is 13508 (triangular elements with global size = 2m), while the total number of nodes is 6939. The selected case study is Al-Adhaim dam, which is an earth dam, located in Diyala governorate at the eastern part of Iraq, crossing Al-Adhaim River with a total length of (3.1 km). The major objective of this study is to derive an empirical equation to calculate the factor of safety for earth dams of similar geometries and materials without the need for sophisticated analysis, by assuming different soil conditions. In addition to the soil parameters (the total weight density ɣ, the angle of internal friction ϕ, the cohesive strength C) for the shell, core and filter within the dam, more parameters have been taken into consideration in predicting the critical factor of safety against slope failure to derive the empirical equation, which are: water depth H (m), coefficient of permeability k (m/s) and Seepage rate Qs (m3/s/m). The values of the computed factor of safety (Fs) using nine installed slope stability methods: Ordinary, Bishop, Morgenstern-Price, Janbu Generalized, Lowe-Karafiath, Corps of Engineers #1 and #2, Spencer and General Limit Equilibrium (GLE) are close to the safety factors values calculated using the general empirical equation which is a function of the soil and hydraulic parameters of the shell, core and filter within the dam.

Listing 1 - 2 of 2
Sort by
Narrow your search

Resource type

article (2)


Language

Arabic and English (1)

English (1)


Year
From To Submit

2018 (1)

2009 (1)