On-line contextual Help

/

Ground Loss 

GEO5

Geotechnical software

« Back to Help

Classical theory

Convergence analysis of an excavation and calculation of the maximum settlement in a homogeneous body are the same for all classical theories. The subsidence trough analyses then differ depending on the assumed theory (Peck, Fazekas, Limanov).

When calculating settlement the program first determines the radial loading of a circular excavation as:

where: σz - geostatic stress in center of excavation
Kr - coefficient of pressure at rest of cohesive soil

The roof ua and the bottom ub deformations of excavation follow from:

where: Z - depth of center point of excavation
r - excavation radius
E - modulus of elasticity of rock/soil in vicinity of excavation
ν - Poisson's number of rock/soil in vicinity of excavation

The maximum terrain settlement and the length of subsidence trough are determined as follows:

where: Z - depth of center point of excavation
r - excavation radius
E - modulus of elasticity of rock/soil in vicinity of excavation
ν - Poisson's number of rock/soil in vicinity of excavation

When the tunnel roof displacement is prescribed the maximum settlement is provided by the following expression:

where: Z - depth of center point of excavation
r - excavation radius
ua - tunnel roof displacement
ν - Poisson's number of rock/soil in vicinity of excavation



Language: english