8 3 ISSN 1999-8716 Printed in Iraq Vol. 09, No. 02, pp. 8 3 -94, June 2016 ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER Asmaa Abdul Jabbar Jamel Assistant Lecture, Civil Engineering, Tikrit University, Iraq [email protected](Received: 2/3/2015; Accepted: 29/4/2015) ABSTRACT: - This investigation concerns to study the quantity of seepage through homogenous earth dam without filter resting on impervious base using computer program SEEP/W (which is a sub-program of Geo-Studio). Using SEEP/W experiments carries out with three different downstream slopes of the dam, three different upstream slopes, three variable downstream head, three different upstream head, three different height of earth dam and three different top width of earth dam. For each run the quantity of seepage have determined. Dimensional analysis was used with helping of the theoretical results to develop an empirical equation in order to determine the quantity of seepage through homogenous earth dam without filter resting on impervious base. Also, Verify the SEEP/W results with an artificial neural network (ANN), and compare with analytical methods. Results show that when compare the suggest equation with artificial neural network (ANN) less than 3% error with SEEP/W results less than 2% error, Dupuit’s solution has more than 20% error and Casagrande’s solution has more than 15% error . Keywords: Discharge, SEEP/W, Homogenous Earth Dam, ANN, Dimensional analysis, Casagrande solution, Dupuit solution Nomenclature q = Discharge (L 3 /T) b = Top width of earth dam (L). H = Height of earth dam (L). h1 = Upstream reservoir head (L). h2 = Downstream reservoir head (L). k = Hydraulic conductivity of dam soil (L/T). FB = Upstream free board of earth dam (L). FD=Downstream free board of earth dam (L). = Angel of downstream slope. = Angel of upstream slope. 1- INTRODUCTION Dams have individually unique structures. Irrespective of size and type they demonstrate great complexity in their load response and in their interactive relationship with site hydrology and geology. Due to indeterminate dams’ nature of many major design inputs, dam engineering has not a stylized and formal science. As practiced, it has a highly specialist activity which draws upon many scientific disciplines and balances them with a large element of engineering judgment; dam engineering has thus a uniquely for challenging and stimulating field of endeavor. Seepage has very important, as seepage affects the stability of Diyala Journal of Engineering Sciences
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ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH … · dams have based on piezometric head data values of seepage discharge of dam [6]. Javad et al. (2012) has developed a novel non-boundary-fitted
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ABSTRACT: - This investigation concerns to study the quantity of seepage through
homogenous earth dam without filter resting on impervious base using computer program
SEEP/W (which is a sub-program of Geo-Studio).
Using SEEP/W experiments carries out with three different downstream slopes of the
dam, three different upstream slopes, three variable downstream head, three different
upstream head, three different height of earth dam and three different top width of earth dam.
For each run the quantity of seepage have determined. Dimensional analysis was used with
helping of the theoretical results to develop an empirical equation in order to determine the
quantity of seepage through homogenous earth dam without filter resting on impervious base.
Also, Verify the SEEP/W results with an artificial neural network (ANN), and compare with
analytical methods. Results show that when compare the suggest equation with artificial
neural network (ANN) less than 3% error with SEEP/W results less than 2% error, Dupuit’s
solution has more than 20% error and Casagrande’s solution has more than 15% error. Keywords: Discharge, SEEP/W, Homogenous Earth Dam, ANN, Dimensional analysis,
Casagrande solution, Dupuit solution
Nomenclature
q = Discharge (L3/T)
b = Top width of earth dam (L).
H = Height of earth dam (L).
h1 = Upstream reservoir head (L).
h2 = Downstream reservoir head (L).
k = Hydraulic conductivity of dam soil (L/T).
FB = Upstream free board of earth dam (L).
FD=Downstream free board of earth dam (L).
= Angel of downstream slope.
= Angel of upstream slope.
1- INTRODUCTION Dams have individually unique structures. Irrespective of size and type they
demonstrate great complexity in their load response and in their interactive relationship with
site hydrology and geology. Due to indeterminate dams’ nature of many major design inputs,
dam engineering has not a stylized and formal science. As practiced, it has a highly specialist
activity which draws upon many scientific disciplines and balances them with a large
element of engineering judgment; dam engineering has thus a uniquely for challenging and
stimulating field of endeavor. Seepage has very important, as seepage affects the stability of
Fig. 1. Dupuit’s solution for flow through an earth dam
Fig. 2. Casagrande’s solution for flow through an earth dam
Fig. 3. Schaffernak’s solution for flow through an earth dam
ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER
Diyala Journal of Engineering Sciences, Vol. 09, No. 02, June 2016
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Fig. 4. Comparison between the SEEP/W discharge and predicted seepage by ANN (artificial
neural network)
Fig. 5. The general section of homogenous earth dam without filter
ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER
Diyala Journal of Engineering Sciences, Vol. 09, No. 02, June 2016
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=1m, BQ) of earth dam with upstream slope 1:3, F) and (bbetween ( Relationship .Fig.6
H=14m
=1m, BQ) of earth dam with Downstream slope 1:2.5, F) and (bbetween ( Relationship .Fig.7
H=14m
ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER
Diyala Journal of Engineering Sciences, Vol. 09, No. 02, June 2016
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with upstream slope 1:3, downstream Q) of earth dam ) and (between (H Relationship .Fig.8
=1m, b=4mBslope 1:2.5, F
Q) of earth dam with upstream slope 1:3, downstream and () Bbetween (F Relationship .Fig.9
=1m, H=14mBslope 1:2.5, F
ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER
Diyala Journal of Engineering Sciences, Vol. 09, No. 02, June 2016
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Fig. 10. Comparison between the calculated discharge from the equation and measuring from
SEEP/W model
Fig. 11. Comparison between the calculated discharges for twenty test with different method.
ANALYSIS AND ESTIMATION OF SEEPAGE THROUGH HOMOGENOUS EARTH DAM WITHOUT FILTER
Diyala Journal of Engineering Sciences, Vol. 09, No. 02, June 2016
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مرشحاتتحليل وتقدير التسرب خالل السدود الترابية المتجانسة بدون
أسماء عبد الجبار جميل مدرس مساعد/جامعة تكريت/كلية الهندسة/قسم المدني
الخالصة
حاويه على مرشح وذات ارضيات غير الأهتمت هذه الدراسة بكميه التسرب خالل السدود الترابية المتجانسة غير ((.Geo-Studio) ( )وهو البرنامج الفرعي للبرنامج الحاسوبيSEEP/Wنفاذة باستعمال برنامج )
ثالث مع (Downstream Slopes)لثالث ميول مختلفة لمؤخر السد SEEP/Wنفذت التجارب باستعمال برنامج (Upstream Head) وثالث ارتفاعات مختلفة لمقدار شحنة المقدم (Upstream Slopes) ميول مختلفة لمقدم السد
Height of)وثالث ارتفاعات مختلفة للسد (Downstream Head) وثالث ارتفاعات مختلفة لمقدار شحنة المؤخرDam) وثالث قيم مختلفة لعرض السد العلوي(Top Width)بعدها تم ،. لكل تجربه تم قياس كمية التسرب خالل السد
باالعتماد على نتائج التجارب للحصول على معادلة رياضية إليجاد (Dimensional Analysis)اجراء التحليل بعديميه التصريف خالل جسم السد الترابي غير الحاوي على مرشح وذي ارضيه غير نفاذة. كذلك قد تم التحقق من ك
التي تم الحصول عليها مع ج، كما وتم مقارنه النتائ (ANN)باستخدام الشبكة العصبية الصناعية (SEEP/W)نتائجونسبه خطا %3العصبية الصناعية نسبه خطا اقل من االساليب التحليلية، حيث اظهرت نتيجة هذه المقارنة مع الشبكة
( ونسبه خطأ Dupuitعند المقارنة مع طريقة ) %22ونسبه خطا اكبر من ((SEEP/Wمع نتائج برنامج %2اقل من (.Casagrandeعند المقارنة مع طريقة ) %32اكبر من
، ANN ،SEEP/Wالشبكة العصبية الصناعية التسرب، السد الترابي المتجانس، التحليل البعدي،الكلمات الدالة: Casagrande Dupuit.