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An-Najah National University Engineering Faculty Civil Engineering Department. Prepared by: Maysaa Qushou Sama Ismail Supervisor: Dr. Isam Jaradanah. Design of Several Foundation Systems For Faculty of Optics. Chapter one presents the introduction of the whole project.
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An-Najah National University Engineering Faculty Civil Engineering Department Prepared by: Maysaa Qushou Sama Ismail Supervisor: Dr. Isam Jaradanah Design of Several Foundation Systems For Faculty of Optics
Chapter one presents the introduction of the whole project. Chapter Two presents general types of foundation system Chapter three presents the structural system of the building that analyzed by two methods which are; tributary area and SAP2000 ver.12 program to find the loads applied on columns and walls. Chapter four presents site investigation report including the main aspects of geotechnical prosperities
The rest chapters present the design of foundations system for the proposed project. In Chapter five, the isolated footing is checked if it can be used or not. while chapter six presents the design of mat foundation, including mat thickness, settlement, mat reinforcement. Finally, chapter seven presents design of pile foundation. Single pile capacity is estimated using several methods, group of piles is found, and pile cap is designed.
CHAPTER TWO REVIEW OF ENGINEERING FOUNDATIONS • Types of Foundations • There are two main types of foundations: • Shallow Foundations • Deep Foundations The lowest part of the structure generally is referred to as the foundation; its function is to transfer the load of the structure to the soil on which it is resting.
Type of shallow foundation(isolated) Types of deep foundation(Friction pile).
CHAPTER THREE STRUCTURAL SYSTEM Description of the Structure The structure that will be analyzed is the Optics Building in An-Najah University.The structure consists of seven stories building; its area is equal to 1200 m². The main objective of this chapter is to find the loads applied on columns using two methods which are; Tributary area method and analysis using software called SAP12.
CHAPTER FOUR SITE INVESTIGATION REPORT Summary of Test’s Results
The bearing capacity can be achieved by software called FTGBC. as shown in pages (28,29). Consider local shear failure, then the cohesion (c) will be reduced by 2/3 and it becomes 50 kN/m². For this case the allowable bearing capacity becomes 120 kN/m².
CHAPTER FIVE DESIGN OF FOUNDATIONS First of all we will check if Isolated footing can be designed, if we find that this method can't be used, then we will design the Mat foundations in chapter six. In our project the space between column not enough to design single foundation and that achieved by (FTGBC) software as shown in pages(31,32).
Overlapping: Figure below demonstrates the overlapping of the stress for the two footings. Calculations: σ1=(136)/(3.2)² = 13.28 ton/m² σ2=(115.1)/(3.5)² = 9.3 ton/m² 9.3+13.28= 18.3 ton/m² > 12 ton/m² This value is not safe . So, we can’t design Isolated footings.
CHAPTER SIX MAT FOUNDATIONS Mat foundations are used to spread the load from a structure over a large area, normally the entire area of the structure. To design Mat Foundations, the depth of the mat has to be found from punching shear equation manually. Then, the maximum moment in (X) and (Y) directions, area of steel and settlement are found from SAP.
To find the depth of foundation, the punching shear equation is used at edge, corner, middle. Φ Vc= (0.85)(0.34)(√fc`)(bo)(d) The results achieved are: d = 60 cm At edge. d = 80 cm at corner. d = 40 cm at middle. d selected = d max.= 80 cm. Then the total thickness of the mat equals: h= d + cover + de h= 80 + 25 + 5= 110 cm
To design mat foundation in sap, spring is used as support under the foundation , so the factor of spring is calculated as the equation below K=12*Qall=12*120=1440kn/m².
Settlement The settlement of each column was taken from SAP12 and we find that the values is less than 1cm.
Maximum moment in (X) and (Y)directions. The values of maximum moment in (X),(Y) directions are taken from SAP12.The figures below show the moment in (X),(Y) direction.
we use the following equations to find (As): ρ = Mu / (fc`* b * d²) As = ρ * b * d The moment between columns gives top steel and the moment at column gives bottom steel. for best designing the number of strip is reduced to three strips only because the moment is approximately equal and the areas of steel also convergent .
CHAPTER SEVEN PILES Piles transmit foundation loads through soil strata of low bearing capacity to deeper soil or rock strata having a high bearing capacity.. Design of Piles: Design of piles used in the project are done using software called Prokon using the parameters below:
Table below shows the values of allowable bearing capacity of piles by Prokon program. Allowable bearing capacity of pile versus pile length and diameter.
Two types of piles are selected in the design of pile foundation in this project, which are shown in the following table: Types of piles Table below shows the allowable applied load and the No. of piles with cap’s dimensions that each group of column has.
Area of steel needed The equations below is used to determine the area of steel : Mu=Pu*e • Mn=BM/ɸ Where: Ø= 0.9 Rn=MN/BD² Vu =(Pu*no.of piles in each side of col.)/total no. of piles in the cap d is assumed and checked if ok or not by Punching shear and Wide beam shear. m= Fy/(Fc*0.85) ρ=1/m * ( 1- √(1((2*Rn*m)/Fy)) ) So , As= ρ*B*d
The areas of steel that calculated for the rest caps are presented in the following table:
