Soil resistivity characterization for geotechnical site investigation

مقدم أطروحة جامعية

Muhammad, Wisam Majid Yaqub

مشرف أطروحة جامعية

Karim, Husayn Hamid
Mahmud, Muhammad Abd al-Latif

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم هندسة البناء و الإنشاءات

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2013

الملخص الإنجليزي

The present study deals with the implementation of two-dimensional resistivity imaging as a geophysical technique for site investigation applied for Al-Aubaidy Electrical Transformation station located in east of Baghdad.

The main objective of this study is to correlate and compare two-dimensional resistivity imaging data with that obtained by conventional site investigation (boring) and determining soil geotechnical properties.

Thirteen spreads with 120 m long and 3m electrode spacing have been surveyed, using Terrameter SAS 4000 by Wenner-Schlumberger and Wenner arrays.

Resistivity data have been analyzed with the assistance of computer software RES2DINV.

The maximum depth of investigation of the surveyed site was about 2Am.

Concerning boring part, the boreholes data of seven boreholes arc analyzed and correlated with data obtained from resistivity, one of these boreholes is drilled for this study.

Fourteen samples from this borehole are collected for the lab tests in addition to in situ tests (standard penetration test (SPT), and ground water table), and also tested in lab as (classification of soil, water content, strength of the soil parameters (c and q) from unconfined compression test, consolidation test, Atterberg limits test and chemical test).

After analyzing and interpreting resistivity imaging sections, it can be concluded that the surveyed site is generally chxactefized by its resistivity decreases with depth having medium - high (3 - 50 ohm.m) at the top of 2 m with higher values for the first geoelectrical layer compared with the second one due to its lower degree of hardness and the presence of silts and sand.

Lower resistivity values appeared below water table (around 2 - 4m) due to the presence of fines with high degree of hardness.

While, relatively very low values (reaching I ohm.m) appeared at third geoelectrical layer due to ground water table.

Comparing the applied arrays, it is found that Wenner-Schlumberger gives better picture about resistivity distribution in both horizontal and vertical variation, while Wenner ar:ray is limited with the variation within the top layers.

Besides, it is concluded that the resistivity decreases with the hardness of the soil and increase in moisture content.

In addition, some geotechnical properties have been evaluated such as porosity, conductivity, total dissolved solids TDS, and relative sensitivity.

Considering correlation of resistivity data with some geotechnical properties, it is found that resistivity is directly proportional to sand and (silts if dry), but it is indirectly proportional to clay, (SO3, gypsum and silt contents if saturated), Atterberg limits, and unconfined compressive strength.

التخصصات الرئيسية

العلوم الهندسية والتكنولوجية (متداخلة التخصصات)

الموضوعات

• الخواص الكهربائية

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-419141