Structural Engineering

In most geotechnical problems, it is too difficult to predict soil and structural behavior
accurately, because of the large variation in soil parameters and the assumptions of numerical
solutions. But recently many geotechnical problems are solved using Artificial Intelligence
(AI) techniques, by presenting new solutions or developing existing ones. Genetic
Programming, (GP), is one of the most recently developed (AI) techniques based on Genetic
Algorithm (GA) technique.
In this research, GP technique is utilized to develop prediction criteria for liquefaction
phenomena in cohesivless soils using collected historical records. The liquefaction formula is
developed using special software written by the authors in “Visual C++” language. The
accuracy of the developed formula was also compared with earlier prediction methods.

In most geotechnical problems, it is too difficult to predict soil and structural behavior
accurately, because of the large variation in soil parameters and the assumptions of numerical
solutions. But recently many geotechnical problems are solved using Artificial Intelligence
(AI) techniques, by presenting new solutions or developing existing ones. Genetic
Programming, (GP), is one of the most recently developed (AI) techniques based on Genetic
Algorithm (GA) technique.
In this research, GP technique is utilized to develop prediction criteria for uplift capacity of
shallow foundations using collected historical records. The uplift capacity formula is
developed using special software written by the authors in “Visual C++” language. The
accuracy of the developed formula was also compared with earlier prediction methods.

It becomes a common practice to strength and repair reinforced concrete columns by wrapping
them with GFRP sheets. The aim of this research is to develop a formula to describe the relation
between the gain of strength of reinforced concrete square columns, their longitudinal reinforcement
and number of warped layers of GFRP sheets. The research is based on simulating loading tests of
a set of 12 reinforced concrete columns with different reinforcement ratios and different number of
warped layers of GFRP sheets using ANSYS software. The outputs of the ANSYS models are
verified using experimental tests results carried out by the author in earlier research. The results of
the study are used to develop a proposed formula to correlate the axial capacity of the warped
square RC column with its reinforcement ratio and the confining stress caused by the sheets.
Values from both proposed formula design and formula of Egyptian Code of Practice (ECP) are
compared with ANSYS outputs and experimental results. The final conclusion is that gained
strength due to confining equals to (confining stress / Fcu).

The behavior of unsaturated swelling soils under changing of moisture content was intensively studied by many researchers since the 1950’s. Many proposed formulas and techniques were used to classify, describe and predict the swelling behavior and parameters of such type of soil. On the other hand, many techniques are used to allow structures to be founded on swelling soils without suffering any damages due to the soil heave. Replacing the swelling soil with granular mixture is one of the most famous and cheapest techniques especially in case of light structures on shallow layer of swelling soil. The aim of this research is to develop a simplified formula to estimate the heave of swelling soil considering the effect of replaced layer. The developed formula is used to estimate the required replacement depth to avoid damage due to excessive heave.

In most geotechnical problems, it is too difficult to predict the soil and structure behavior accurately, because of large variation in soil parameters and the assumption of the numerical solutions. But recently many geotechnical problems are solved using Artificial Intelligence (AI) techniques by presenting new solutions or developing the existing ones.
The aim of this thesis, is to apply one of the most recently developed (AI) techniques called "Genetic Programming" (GP) in geotechnical problems, trying to fined new solutions or enhancing existing ones using lhis technique. (GP) technique uses a set of field or laboratory test results to generate a simple closed form equation describes the considered phenomena. This thesis focuses on applying (GP) technique to predict
a) Uplift capacity of shallow footing, b) Liquefaction potential of soil, c) Compaction of granular soil and
d) Clean sand behavior under compressive stresses. The research results show that (GP) technique
generates very precise formulas for the first and second applications and good precision formulas for the third and forth applications.
Keywords: Artificial Intelligence, Genetic Programming, geotechnical, Uplift capacity, Liquefaction, Compaction, Sand behavior.

The development of statistics and probability puts The expression (Probability of failure ) instead of ( Factor of safety) in most stability problems in geotechnical field, because it takes into consideration the non-uniformity of soil parameters as random variables since to obey the probability rules, which known as (Risk Analysis Theory). So using this method to analyze the stability problems gives more accurate results than the conventional method of factor of safety. This research is concerned with applying lhe risk analysis theory in case of uplift. foundations. The considered types of foundations are: • Pad and chimney • Tension piles • Anchors The aim of this thesis is to recommend the most suitable method and evaluate the corresponding factor of safety to predict the capacity of uplift foundation according to soil conditions and target probability of failure. Keywords: Risk Analysis, Probability, Uplift, Pad, Chimney, Pile, Anchor

Laterally loaded pile is a famous case of soil-structure interaction problem which was intensively
studied by many researchers before. The techniques used to predict the behavior of laterally loaded piles were
developed with increasing of the available computational capabilities from closed mathematical formulas to finite
differences technique and finally linear finite elements technique. Recently, very sophisticated 3D elasto-plastic nonlinear
finite element models were used to accurately predict that behavior. Unfortunately, those sophisticated models
are too complicated to be used in practical design. Hence, the aim of this research is to introduce a much simpler and
practical approach to predict the behavior of the laterally loaded concrete piles considering the nonlinear effect of
concrete cracking. Special calculating tool based on finite elements is developed to carry out a parametric study of the
behavior of a set of 24 piles with different aspect ratios, reinforcement ratios, relative stiffness and head constrains. The
validity of the calculating tool is checked against case history field tests. The results of the parametric study show three
different failure modes according to the flexibility of the pile. Comparing the results with the formulas of ECP (202/4)
shows the matching in the ultimate lateral capacity, while the ultimate lateral deformations are about (127 to 132%) of
the code prediction.

improving soil parameters using dynamic compaction of was intensively studied by many researchers since 1980’s. Earlier researchers depended on statistical analysis of many case studies and soil dynamic principals to develop empirical formula used in designing dynamic compaction procedure. Recent researchers used different finite element models to describe the behavior of soil under dynamic compaction; those models varied between 1-D simple model and up to 3-D sophisticated ones. The aim of this research is to introduce a simple mathematical approach to simulate ground deformations and soil parameters improvement due to dynamic compaction. The proposed approach consists of two equations, the 1st one used to calculate the ground settlement due to one temper drop, the 2nd one used to calculate the updated soil parameters due to the ground settlement from the previous drop. By applying the two equations successively, both ground settlement and soil parameters improvement could be calculated after each tamper drop. The proposed approach was applied on four case studies and its results were so close to measured ones. The proposed approach could be used in designing or testing the dynamic compaction procedures and also in monitoring the quality of execution by comparing the measured settlement after each drop with calculated one.

The increasing of high raise and heavy industrial construction industry causes increasing in structural columns loads and accordingly their cross sections, on other hand; architectural and mechanical requirements limit the available spaces for columns. Commonly, three alternatives are used to reduce column size to fit into the available space with same axial capacity, the first is to use higher concrete strength, the second is to use composite column (enclosed or in-filled) and the third is to use high strength steel column. In this research, a parametric study is carried out to figure out the impact of each alternative on the structural behavior and direct cost of the project. The study is based on average materials, labor and equipment rates in USA in 2016. Study results indicated that optimum alternative is to use higher concrete strength up to 1.4 times the concrete strength of floors beyond this limit, composite column (enclosed or in-filled) is recommended. Finally high strength steel column is the only alternative for very compacted columns.

The fast growth in digital image applications such as web sites, multimedia and even personal image archives encouraged researchers to develop advanced techniques to compress images. Many compression techniques where introduced whether reversible or not. Most of those techniques were based on statistical analysis of repetition or mathematical transforming to reduce the size of the image. This research is concerning in applying Genetic programing (GP) technique in image compression. In order to achieve that goal, a parametric study was carried out to determine the optimum combination of (GP) parameters to achieve maximum quality and compression ratio. For simplicity the study considered 256 level gray scale image. A special C++ software was developed to carry out all calculations, the compressed images was rendered using Microsoft Excel. Study results was compared with JPEG results as one of the most popular lossy compression techniques. It is concluded that using optimum (GP) parameters leads to acceptable quality (objectively and subjectively) corresponding to compression ratio ranged between 2.5 and 4.5.

— This research work mainly investigates the local production of 12 built up GFRP I-beams using Hand Lay-Up production method (since up-till now there is no pultrusion industry in Egypt). Overall strength characteristics of these beams will determined experimentally and compared to those manufactured by the Pultrusion process. This comparison will help to estimate to how extent the locally manufactured beams (by Hand Lay-Up technique) can be used in full permanent structures (like pultruded beams) or at least used in light and temporary structures. In order to achieve this goal, the experimental study was divided into two stages: The first stage is to manufacture GFRP plates using glass fibers and polyester. Two types of plates were produced one for flange plates and the other for web plates. These two types of plates are different in fibers orientation of different layers within the plate thickness in order to reach the possible higher tensile and flexural strength for flange plates and possible higher shear strength for web plates. Longitudinal and transverse tensile, compressive, and flexural strength for these two types of plates were experimentally determined using coupons tests. The second stage is to produce built-up GFRP I-beams using the aforementioned plates and composite angles. The overall stiffness and modes of failure of these beams were experimentally determined. The obtained results were compared with those of pultruded I-beams manufactured in the United States by pultrusion process. Also three different connecting methods for the 12 tested beams were investigated, namely: Bonding – Bolting – Bolting/Bonding connecting techniques. Of course it is expected that some local fabrication parameters (like fiber and polymer properties available in the local market, labour, temperature, polymer curing …etc) are expected to affect the properties of the fabricated beams specially that these beams are manufactured manually.

— Surface or shallow compaction is one of the earliest, cheapest and commonly used techniques to improve the physical and mechanical properties of loose soil specially for imported structural fill. It is simply rearranging of soil particles to reduce air ratios using surface static or vibrating mechanical effort. Usually, shallow compaction procedure includes subjecting the loose soil to certain number of compacting equipment passes to archive the accepted compaction level; this number of passes is a function of many parameters such as type of soil, initial soil parameters, compacting equipment characteristics and thickness of soil lift. International codes, specifications and handbooks include just guidelines about the required number of passes; accordingly, it is usually determined based on personal experience and field trials. This research has two goals, the first is to estimate the properties improvement of certain natural surface loose soil under certain surface compaction procedure by calculating the enhancement in soil properties after each pass and updating the soil properties for next pass calculations. The second goal is to use the previous approach to develop set of equations to design surface compaction procedure for imported structural fill, this includes calculating minimum compaction equipment characteristics, maximum lift thickness and minimum number of passes to enhance certain imported fill from certain initial condition to certain final condition. The proposed approach for the first goal was verified using case studies and showed good matches, and the developed designing equations for surface compaction procedure were verified using case studies and showed good matches.

Static cone penetration test (CPT) is a broadly satisfactory and dependable geotechnical in-situ apparatus that gives brisk and honest substantial measure of data about soil classification, stratification and properties. Un-drained shear strength of clay (cu) is one of the principle soil parameters that could be sensibly evaluated from the (CPT) results, as it is specifically connected to the tip resistance through the experimental cone factor (Nk). Earlier researches showed that (Nk) value depends on type of soil, nature and stress history conditions and many other variables. Construction development in some locations with thick deposits of soft to very soft clays motivates extensive researches to define the reasonable value of the (Nk) factor for such types of clay. The performed study concentrated on utilizing the genetic programming technique (GP) to predict (Nk) value of clay using the consistency limits that can be easily determined in the laboratory. A set of 102 records were gathered from the CPT site investigations and corresponding consistency limits and other physical properties experiments, were divided into training set of 72 records and validation set of 30 records. Both (GN7) & (MEPX) software were used to apply (GP) on the available data. Four trials for each software with different chromosome lengths were performed to correlate the (Nk) factor with the clay consistency limits, water content (wc) and unit weight (γ) using training data set, then, the produced relations were tested using the validation data set. The four generated formulas using (GN7) showed accuracies ranging between 93% and 97% and coefficient of determination (R 2) ranging between 0.7 and 0.9, while the other four formulas form (MEPX) showed accuracy not exceeding 95% and coefficient of determination (R 2) ranging between 0.45 and 0.75.