The theoretical concepts used in the PYWALL software extend
beyond the conventional method of analysis and design of flexible
retaining walls based on limit-equilibrium theory. As a difference to
conventional practice, the PYWALL method includes the effects of
soil-structure interaction which helps to provide a practical estimate
of the wall deflections and load demands.
Modern methods of analyses of the behavior of retaining structures
consider realistic soil conditions and relevant details of the
structural system. Therefore, a rational method of analysis and design
must include the nonlinear soil-resistance-displacement relationships,
pile spacings, penetration depths and structural properties. PYWALL
considers soil-structure interaction by using a beam-column model and
can analyze the behavior of a flexible retaining wall or soldier-pile
wall with or without tiebacks or bracing systems.
Features
Simplified evaluations of the impacts of staged
construction (for up to 5 stages).
Quick and combined observation of results of wall
deflections and bending moments in different
construction stages.
Evaluate short and long-term wall response for
user-defined soil properties and loading
conditions.
p-y curves for weak rock, soft clay, stiff clay
with and without free water, sand, silt (c-phi soil), and
strong rock (Vuggy Limestone).
View combined output of lateral movements, shear and
bending moment along the length of the wall and in a
single page for quick observation of results and to help
users in the verification process.
A sloping backfill can be specified and when
selected, the program takes into account this slope
angle when generating earth pressures of triangular
distribution acting against the wall.
Automatically generate active earth pressures with
triangular distributions based on the traditional
Rankine theory. When selected, users may also specify a
constant load factor to increase or decrease the
magnitude of earth pressures generated by the
program.
In addition to earth pressures, concentrated loads
may be specified at any point(s) in the wall. The
concentrated loads can be a specified lateral load,
bending moment or axial load.
Additional surcharge loads may be specified in the
back side of the wall. Four types of surcharge loads can
be specified: area load, point load, line load and/or
strip load.
Struts or braces may be specified at any height(s) of
the wall. The stiffness of these elements can be modeled
as linear elastic springs or fully nonlinear
springs.
Optionally, users may calculate externally and input any
type of earth-pressure distributions. The program can
interpolate linearly between inputted values of pressure
placed at different depths.
Specify deflections or slopes at any point in the height
of the wall. This input option allows designers to make
a better simulation of braces having limited movements
or to model specific conections between braces and
wall.
Flexural stiffness of the wall may be varied and/or
linearly interpolated at different wall heights.
Soil-resistance (p-y) curves can be internally
generated by the program for the following 7 types of
soils: soft clay, stiff clay with or without free water,
sand, silt (c-phi soil), weak rock and
rock. Internally-generated p-y curves may be printed for
reviews or reference.
Users may optionally input their own soil-resistance
(p-y) curves at any desired depth. PYWALL uses
double-precision algorithms to reach better solutions in
the nonlinear iterations.
User-defined multipliers can be specified to increase or
reduce the soil resistance (p-y curves) at any
depth of the wall below the dredge line. For instance,
this feature may be used in seismic conditions to reduce
the response of liquefied layers, or to consider creep
effects for long-term conditions or for closely-spaced
piles.
The program provides users with standard cross-section
data base for H-piles and Sheet-piles, and as well as
user-specified cross sections.
