# هل يمكن تمثيل قاعدة على خرسانه عاديه فى برنامج سيف

#### last.gladiator

##### عضو نشط
السلام عليكم ورحمه الله وبركاته
يعنى حضرتك تقصد انى لو مثلا عندى
KN/m2 120 = B.C
اضربها فى نسبه القاعدة العاديه / القاعدة المسلحه
واجيب mod B.C
وعلى اساسها احسب Kspring
اللى هتساوى 120*B.C*area served

هل دة اللى حضرتك تقصدة ولا انا فهمت غلط؟؟؟

#### عمران الفاتح

##### عضو جديد
first of all my deep regards to all
second issue, let us examine your view point from structural analysis
what you would like to model??this is the question

the answer is : You will model a shell element
what is the discription of shell element ?? The answer is the shell elemnt is an area with two dimensions length and width

the third question is how we can input the thickness of the shell element?? The answer is we can add the thickness by using prperties of material (concrete , steel , or whatever) and then we decide the thickness

the ques 4 is how we can model the soil ? The structural engineers solve this problem by using the concept of the spring

and we can explain this concept later on

now, we define the problem
let us now examine your problem and try to find a structural solution
you need to define two layers of a cross section
the first layer is a plain concrete and the second layer is a reinforced concrete
to draw a shell area contains two layers this is not valid in this software.
Second method of thinking ,is to draw two shell elemnts to be coincide together, and this is not valid by finite element
third method to model this problem by using solid elelmet not by using a shell elemnt but solid elemnt is not valid in safe program

let us now using differnet method of thinking to find a practical solution

we use the plain concrete to increase the area of footing then we decrease the bearing pressure between plain concrete and the soil and we increase the bearing pressure between the plain concrete and reinforced concrete

in other words if the area of plain concrete say 2mx2m = 4m2
and the area of reinforced concrete is 1.5mx1.5m = 2.25 m2

so if the bearing capacity of soil is 1 kg/cm2 , when we design the reinforced concrete we can consider the bearing is 1kg * 4/2.25m2 will be around 1.7kg/cm2

so in this case what you can do, increase the k spring of the soil in the safe program around 20% of the bearing capacity of the soil

then when you check the bearing capacity under the reinforced concrete if this value does not exceed 1.7 (for example) it means your work is okay
this is one idea and if i find any other solution i will tell you

وماذا عن وزن الخرسانة العادية كيف يتم إعتباره

شكرا جزيلا