Both the moment of inertia and the section modulus are measurements of the relative stiffness of a cross section of steel piling.
Section modulus of steel sheet pile.
The plastic section modulus can be up to 25 higher than the elastic section modulus which leads to a significant reduction of the overall cost lighter sheet piles.
When calculating the stress in a steel pile for example the formula using i is stress m y i.
When the pz 27 section was introduced in the 1940 s its section modulus of 30 2 in3 ft was almost three times that published for the arch section with the identical weight per square foot of wall.
The allowable stress of the material is a function of the material itself.
This section subsequently became the all time most popular sheet piling section in history.
Pz ps hot rolled steel sheet pile section width w in mm web tw in mm maximum interlock strength k in kn m minimum cell diameter ft m cross sectional area in2 ft cm 2 m weight elastic section modulus in3 sheet cm3 sheet moment of inertia in4 sheet cm4 sheet coating area pile lb ft kg m wall lb ft2 kg m2 both sides ft2 ft.
Section modulus 650 k ft ft x 12 in ft 31 2 k in 2.
Smin minimum section modulus both the allowable bending moment and the section modulus are specified as per lineal foot or meter of wall.
Pzc sheet piling properties.
Therefore the required section modulus is 250 in 3 ft.
For instance for u piles a reduction of the section modulus and of the moment of inertia may have to be considered.
The strength of sheet piling to resist bending is a combination of the shape of the section and the material out of which it is made.
Pzc profiles should always be the designer s first choice in order to provide the end user a highly efficient ratio of section modulus to weight.
The us army corps of engineers design of sheet pile walls engineer manual from 1994 recommends accounting for a safety factor for the allowable bending stress of 50 50.
Pzc profiles are named for their strength in metric designations.
Click here for a full guide to pzc steel sheet piling properties.
For example pzc 18 has a section modulus of 1 800 cm3 meter.
The major difference is that i moment of inertia is used for more general calculations.
Ec 3 5 considers also several reduction factors.