STRUCTURAL ENGINEERING

1. Technical Report
Volvo Service Center "Concrete Floor Analysis"
Client: SPRING GROUP.
1. Problem Description:
a Reinforced concrete slab with (150 mm) thickness, under a service loading of
Transport (Carriage) Trailer with total weight of (58.5 TON), according to AASHTO
& ACI.318.08 international codes.
Attached documents:
Table (4.8) Arrangement of Trailer axel loads for both wheel side (left & right) and
geometrical dimensions for trailer wheel axle.
Fig 1.1 first case study “Single wheel axel located on Edge of Slab”
Fig. 1.2 second case study “Single wheel axel located on middle-span of Slab”
Fig. 1.3 third case study “Double wheels axel located on middle-span of Slab”
Fig 2.2 typical dowelled contraction (reinforced and unreinforced) slab joint
Fig 2.3 typical dowelled expansion slab joint
2. Basic assumption:
2.1 Concrete compressive strength is 35 MPa and steel yielding strength is 420
Mpa for BRC steel mesh.
2.2 Soil minimum bearing capacity is 14 TON/m2
.
2.3 Vertical applied pressure (axle loads) is uniformly distributed form top
surface to bot by angle of (45 degree).
2.4 Soil bearing strength calculation is based on Safety Factor of (F.S. = 3.0).

2. 3. Strength Requirements:
3.1 concrete slab checking part:
3.1.1 bearing strength
3.1.2 bunching (sheering) strength
3.1.3 serviceability “max allowable deflection”
3.2soil foundation checking part:
3.2.1 contact pressure “soil bearing capacity”
3.2.2 max allowable settlement “international code req. ”
4. stress calculation:
4.1Soil Part:
Wheel axle loading is based on attached Table (4.8) and Table (FLM4) in Euro-code
number (EN 1991-2) for both: Trailer Truck and Cargo Carriage Truck. Taking the
worst-case scenario (1st
and 3rd
item in attached table 4.8) to represent our validation
calculation.
FIRST CASE: refer to attached figure number (1.1)
surface pressure = (applied load, ton) / (contact surface area, m2
)
q1 = P / A
q1 = 3.5 / (0.22 * 0.32) = 49.72 ton/m2
top soil pressure = surface pressure * reduction factor
q2 = q1 * A1 / A2
q2 = 49.72 * (0.22 * 0.32) / (0.62*0.37) = 15.26 ton/m2
> 14.0 ton/m2
(NOT OK.)
Note: the probability of above “problem” result is only occurs at joint area which
represent no more than 5% of total concrete slab area, and this problem could be

3. resolved by increasing the strength of the expansion joint “as shown in Fig.(2.2) for
reinforced joint”.
SECOND CASE: refer to attached figure number (1.2)
surface pressure = (applied load, ton) / (contact surface area, m2
)
q1 = P / A
q1 = 3.5 / (0.22 * 0.32) = 49.72 ton/m2
top soil pressure = surface pressure * reduction factor
q2 = q1 * A1 / A2
q2 = 49.72 * (0.22 * 0.32) / (0.62*0.52) = 10.84 ton/m2
< 14.0 ton/m2
(OK.)
THIRD CASE: refer to attached figure number (1.3)
surface pressure = (applied load, ton) / (contact surface area, m2
)
q1 = P / A
q1 = 6.5 / (0.54 * 0.32) = 37.572 ton/m2
top soil pressure = surface pressure * reduction factor
q2 = q1 * A1 / A2
q2 = 37.572 * (0.54 * 0.32) / (0.84*0.62) = 12.476 ton/m2
< 14.0 ton/m2
(OK.)
Allowable settlement of foundation was checked by structural analysis software
“Staad.pro” and the resulted settlement is 11.8 mm less that 25 mm, which is accepted.
__________________

4. 4.2 Concrete Slab Part:
Bearing (crushing strength):
a. Allowable bearing stress (on full area) = 0.25 *fć
= 0.25 * 35 = 8.75 MPa
contact pressure (3rd
case) = 37.572 * 0.01 = 0.376 << 8.75 (OK.)
b. Allowable bearing stress (on one-third area) = 0.375 *fć
= 0.375 * 35 = 13.13 MPa
contact pressure (1st
case) = 49.72 * 0.01 = 0.497 << 13.3 (OK.)
Punching strength:
a. Nominal slab shear strength is :
√ ̅
√
Applied punching load (1rd
case), P = 3.5 < 10.476 ton
b. Nominal slab shear strength is:
√ ̅
√
Applied punching load (3rd
case), P = 6.4 < 22.63 ton

6. 320
220
Fig. (1.1) First case - Loading Area
Wheel Axle load on Edge of Concrete
Slab
P

7. 320
220
Fig. (1.1) Second case - Loading Area
Single Wheel Axle load at middle of Concrete Slab
P

8. 320
540
Fig. (1.3) Third Case-Loading Area
Double Wheels (Tandem) Axle load at middle of of Concrete Slab
2P