Odkaz jsme Vám odeslali na email.

Nepodařilo se nám odeslat odkaz na váš email. Zkontrolujte, prosím, Váš email.

Online nápověda

GEO5

Stromeček
Nastavení
Produkt:
Program:
Jazyk:

Analysis of Bearing Capacity of the Nails

For each nail the following bearing capacities are either computed or input:

Rf

-

nail head strength

Rt

-

nail strength against breaking

Tp

-

pull-out nail bearing capacity

Strength characteristics of a nail represent the basic parameters to compute the total bearing capacity of a nail.

The nail strength against breaking follows from:

where:

Rt

-

strength against breaking

ds

-

nail diameter

fy

-

strength of nail material

SFt

-

factor of safety against breaking

The pull-out nail bearing capacity is calculated by one of the following ways:

1. calculate from ultimate bond strength:

where:

Tp

-

pull-out nail bearing capacity [kN/m]

d

-

hole diameter

gs

-

ultimate bond strength

SFe

-

factor of safety against pull-out

2. calculate from effective stress

where:

where:

Tp

-

pull-out nail bearing capacity [kN/m]

d

-

hole diameter

σz

-

vertical geostatic stress

φ

-

effective angle of internal friction of soil

c

-

effective cohesion of soil

SFe

-

factor of safety against pull-out

3. calculate according to HA 68/94

where:

Tp

-

pull-out nail bearing capacity [kN/m]

d

-

hole diameter

σn

-

average radial effective stress

φ

-

effective angle of internal friction of soil

c

-

effective cohesion of soil

SFe

-

factor of safety against pull-out

Average radial effective stress σn is calculated by following formula:

where:

σz

-

vertical geostatic stress

where:

Nail head strength is evaluated by formula:

where:

l

-

nail length

Smax

-

maximum spacing of nails in a structure

Rt

-

nail strength against breaking

Tp

-

pull-out nail bearing capacity

SFf

-

factor of safety of nail head strength

If the nail is not anchored to the structure cover, it is possible to set the nail head strength to zero.