Slab-on-grade subjected to concentrated loads

This tool calculates the capacity of slabs-on-grade subjected to concentrated loads, using the Shentu method.

D(kip)

Dead load

Constraints
min: 0step: 1
L(kip)

Live load

Constraints
min: 0step: 1
b_p(in)

Base plate width

Constraints
min: 0step: 1
t_s(in)

Slab / member thickness

Constraints
min: 0step: 0.5
k_s(pci)

Modulus of subgrade reaction

Constraints
min: 0step: 10
f_c(psi)

Specified concrete strength

Constraints
min: 1000step: 100
φ

Resistance factor

Constraints
min: 0step: 0.05
slab-on-grade with point load

Calculation Steps:

    Design Loads
    • P_s

      Service load

      kip
    • P_f

      Factored load

      kip
    Concrete Properties
    • f_t

      Concrete modulus of rupture

      psi
    • E_c

      Concrete modulus of elasticity

      psi
    SOG Capacity
    • λ_s

      Size effect factor; 1.0 for slabs less than 7" thick, 0.85 otherwise

    • R_1

      Equivalent radius of contact area

      in
    • P_n

      Nominal capacity per Shentu method

      kip
    • φP_n

      Factored capacity

      kip
    Radius of Influence
    • r_k

      Radius of relative stiffness

      in
    • r_i

      Radius of influence; no other loads should be present within this distance

      in
    Result
    • util

      Utilization ratio

    • NG (221% utilized)

    • The methodology above is not explicitly provided for in the concrete code. Use judgement about appropriate application and factor of safety. No other loads should be present within the radius of influence.

    References
    User Notes: