Three dimension electricral resistivity and IP imaging for soil layers invistgation at uotbaghdad

مقدم أطروحة جامعية

Aziz, Nida Ahmad

مشرف أطروحة جامعية

Karim, Husayn Hamid
al-Qaysi, Mahmud Rashid

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم هندسة البناء و الإنشاءات

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2012

الملخص الإنجليزي

Electrical resistivity techniques are considered to be the most applicable for geological, geotechnical, environmental and archeological studies.

The use of 2D and 3D resistivity surveys has enabled us to mapping complex geological, detecting cavities, walls and other manmade structures that were not previously possible with conventional 1-D resistivity surveys.

ABEM Terrameter SAS 4000 was used for data collection.The field work was conducted in two different sites in University of Technology, Baghdad, Iraq.

The survey design is based on choosing the electrode configuration taking into account available information about the site and the advantages of the ERI technique.

2D and 3D electrical resistivity and IP imaging sections, have been obtained.

The data analysis comprises of 2D inversions using the RES2DINV software.

The obtained data analyzed, and 3D models of the subsurface was generated using 3D inversion software called RES3DINV and the Slicer Dicer software.

For the 1st site, two dimensional surveying was carried out along 3 profiles using Wenner and Wenner-Schlumberger arrays with length of 40, 60 and 60 m and electrode spacing 1, 1.5 and 1.5 m respectively.

The max depth of penetration is ranged between 7 to 11m showing two geoelectrical layers: the upper layer with high resistivity (10-26 ohm.m) represents the top soil layer (loamy soil) shows inhomogeneous (4-9 ohm.m) represents the clayey layer.

Regarding the 2nd site, 2D and 3D resistivity imaging were conducted along 7 parallel lines and 14 orthogonal lines.

The depth of investigation ranges between 4 to 8 m, and resistivity values range from <1 to 292 ohm.m.

Two electrical layers were recognized: the upper layer with high resistivity (7-71 ohm.m) represents the loamy soil extends to a depth around 1.3 m; and the second layer with low resistivity (<1-9 ohm.m) represents the clayey layer.

Some distinguishable low and high electric zones are appeared reflecting the inhomogeneity in deposits.

The IP values for the 2nd site are ranging from (-1 to 14) mV/V with good agreement with resistivity data, where high chargeability are associated with low resistivity.

Two 3D images were created for the 2nd site, using Wenner-Schlumberger configuration.

The 1st image consists of 14 parallel lines with spacing of 1.5 m, and 3 perpendicular tie lines.

While, the 2nd image is resulted from a perpendicular rectangular grid (40 ×20) m includes 4 parallel lines and 7 orthogonal lines with spacing of 7 m in both directions.

3D electrical resistivity images reflect a clearer picture for resistivity distribution which gives 14 different depth slices for the estimated model with depth interval about 0.25m.

The 1st 3D image was better in definition, details and layer delineation than the second.

The 2D and 3D imaging sections showed a good agreement with the drilling data obtained from the available boreholes within the area.

التخصصات الرئيسية

العلوم الهندسية والتكنولوجية (متداخلة التخصصات)

الموضوعات

• الخواص الكهربائية

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-419569