Civil Engineering Reference
In-Depth Information
Drained
1
2
0.1
3
4
5
c
v
= 1 (uniform)
6
u= 100 at all nodes
at time t=0
7
8
9
10
nels np_types
10 1
prop(cv)
1.0
etype(not needed)
ell
0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
dtim nstep theta npri nres ntime
0.001 2000 0.5 100 11 1000
loads(i),i=1,neq
100.0 100.0 100.0 100.0 100.0 100.0
100.0 100.0 100.0 100.0 100.0
fixed_freedoms,(node(i),value(i),i=1,fixed_freedoms)
1
1 0.0
Undrained
11
Figure 8.2
Mesh and data for Program 8.1 example
Figure 8.1. Note, however, that the matrix-by-vector multiplication on the right hand side
could be done using element-by-element summation, avoiding storage of one large matrix.
Figure 8.2 shows a string of 10 elements attached end to end, representing a 1D layer of
saturated soil with a total depth of 1.0. The layer is subjected to a uniform initial excess pore
pressure distribution of 100.0 and is drained at the top only. The material property required
in this analysis is the coefficient of consolidation
(analogous to
EA
in Program 4.1 and
kA
in Program 7.1). The objective of the analysis is to compute the excess pore pressure
distribution and the average degree of consolidation as a function of time.
The data involve reading the number of elements
nels=10
, and the number of property
types
np types=1
. In this case the layer is uniform, so with
np types=1
the
etype
data is not needed. The 10 element lengths
ell
are read, and in this example are all the
same length and equal to 0.1.
The next line of data refers to the time-stepping and the output parameters. The three
time-stepping parameters are the calculation time step
dtim
, read as 0.001, the number of
c
v
