research centers


Search results: Found 4

Listing 1 - 4 of 4
Sort by

Article
Volume Change Measurements for Unsaturated Soils in Triaxial Equipment with Double Wall Cell
قياس التغيرات الحجمية للترب غيرالمشبعة باستخدام خلية فحص الانضغاط الثلاثي المحاور ذات الجدار المزدوج

Authors: Muayad A. Al-Sharrad --- Domenico Gallipoli --- Simon J. Wheeler
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2013 Volume: 31 Issue: 19 Part (A) Engineering Pages: 173-184
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The paper gives a brief description of double wall cell triaxial equipment for testing soil samples under unsaturated conditions and presents results of some of the calibrations necessary to achieve accurate measurements of inner cell water volume, pore water volume, pressure, load and displacement. The calibration of the measurement devices showed linear relationships between the raw readings and applied values with the regression constants differ from 1 and 0. The result of apparent volume change calibrations showed significant correlation between cell water volume fluctuation and temperature fluctuation inside testing room. A correction to the measured volume was therefore required to reduce the effects of long-term temperature fluctuation on the measured volume. Investigation of the accuracy of volume change measurement with the double wall cell showed excellent matching between the inner cell volume change and pore water volume change under saturated conditions, indicating the high reliability of the double wall system for apparent volume change measurements.

يعطي البحث وصف مختصر لجهاز فحص الانضغاط الثلاثي المحاور لاجراء اختبارات على ترب غير مشبعة ويصف البحث مجموعة من المعايرات الضرورية لضمان قياسات دقيقة لحجم الماء في الخلية الداخلية وحجم الماء الموجود في الفجوات ومقاييس الضغط والحمل والازاحة العمودية. تشير نتائج المعايرة الى علاقة خطية بين القيم المسلطة الحقيقية والقيم المقروءه وان معاملات الانحدار الخطي مختلفة عن صفر و واحد. تشير معايرة التغير الحجمي الظاهري الى علاقة وثيقة بين التغير الحجمي وتغير درجة حرارة غرفة الاختبارات. لذلك اقترح معامل تصحيح لتقليل تذبذب درجة الحرارة. يشير تحري دقة قياس التغير الحجمي باستخدام تقنية الخلية الداخلية الى توافق كبير مع التغير الحجمي المقاس باستخدام حجم ماء الفجوات في حالة الاشباع مما يؤكد موثوقية القياس باستخدام هذه التقنية.


Article
Two-Dimensional Consolidation Analysis of Partially Saturated Earth Embankment Under ITS Self Weight by Using the Finite Element Method

Authors: Abdul Kareem E. Zainel --- Yousif J. Al-Shakarchi --- Omar Al–Farouk S. Al-Damluji
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2008 Volume: 14 Issue: 1 Pages: 2232-2255
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

This paper studies the two-dimensional analysis of the consolidation process for partially saturated soils applied to an earth embankment mainly from the theoretical point of view. The method of finite elements is used to find a numerical solution to describe the behavior of soils during consolidation. Moreover, this study was carried for both, isothermal and non-isothermal cases.The case of two–dimensional, plane strain consolidation is considered, as it is widely needed in the studies of soil mechanics. The parameters studied are displacement in the y–direction, pore water pressure, pore air pressure, and temperature.The embankment was constructed in Basrah - Iraq, where the temperature is usually high at most days of the year. It is believed that it is more realistic to model the embankment as a partially saturated soil rather than a fully saturated soil as was done before.The study reveals that: –- The consolidation process is affected by the degree of saturation. As the paths in the soil that are used by the pore–water and/or the pore–air may transfer from one state (open path) to another state (closed path) and vice versa. - The pore–water and the pore–air pressures are affected by temperature. The pressure increases when the temperature increases (for a constant volume). This is usually the case inside the partially saturated soil. Temperature can affect indirectly the soil skeleton as a result of the change in pore–air and pore–water pressures.- The vertical displacement for partially saturated soil consolidation under self weight loading is noticed to have almost regular settlement. Then, there is an accelerated settlement due to the dissipation of the air and water pressures. After a while (after excess pressures dissipation), there will be a classical consolidation form.


Article
A modified Suction-controlled Triaxial Equipment
جهاز مطور لفحص القص الثلاثي المحاور باستخدام تقنية ضغط الامتصاص

Loading...
Loading...
Abstract

The paper presents a modified equipment for triaxial testing of soil samples under unsaturated as well as saturated conditions. The equipment is capable of performing various types of hydro-mechanical loading including wetting and drying stress paths under constant or varying net stresses. The suction is controlled/ measured by using axis translation technique. Initial investigation on the performance of the testing system after appropriate calibrations had been conducted indicated good level of accuracy in measuring various soil properties.

يعرض البحث جهازاً مطوراً لفحص القص الثلاثي المحاور للترب غير المشبعة بالاضافة الى تلك المشبعة. يمكن استخدام الجهاز لاجراء الفحصوصات المزدوجة الميكانيكية- الهيدوليكية بما في ذلك اجراء دورات الترطيب والتجفيف تحت تاثير اجهادات ثابتة او متغيرة ويعتمد الجهاز على مبدأ تقنية نقل المحور لتسليط ضغط الامتصاص. اثبتت المعايرات التي اجريت على الجهاز دقة القياسات المسجلة لخصائص التربة.


Article
Variation of Compression Index and Swelling Index with Degree of Saturation in Unsaturated Soils
تغير معامل الانضغاط و معامل الانتفاخ مع تغير درجة التشبع في الترب غير المشبعة

Authors: Ala Nasser Aljorany علاء ناصر الجوراني --- Abdul Kareem Esmat Zainal عبدالكريم عصمت زينل --- Mustafa Yasen Namah مصطفى ياسين نعمه
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2015 Volume: 21 Issue: 6 Pages: 77-89
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

The variation of compression index Cc and swelling index Cs with the degree of saturation S was studied on unsaturated and fully saturated soils for different degrees of saturation (100%, 91%, 85%, 75%, 60%), several mathematical equations were found to describe these relationships, these equations can be used to predict settlement during the consolidation process in unsaturated and fully saturated soils.

تم دراسة تغير معامل الانضغاط و معامل الانتفاخ في الترب غير المشبعة والمشبعة كليا لعدد من درجات التشبع (100% , 91% , 85% , 75% , 60%) وتم ايجاد عدد من المعادلات التي تمثل العلاقات بين تلك المعاملات و درجات التشبع المختلفة, ويمكن لهذا المعادلات ان تستخدم لتخمين الهبوط الحاصل في التربة خلال عملية الانضمام في الترب غير المشبعة والترب المشبعة .

Listing 1 - 4 of 4
Sort by
Narrow your search

Resource type

article (4)


Language

English (4)


Year
From To Submit

2015 (2)

2013 (1)

2008 (1)