New Product Introduction

Pile Analysis Program 'LPILE' and 'GROUP(3D)' GEOTECHNICAL SOFTWARE

ENSOFT havs cutting-edge civil engineering applications such as LPILE Plus v5.0, GROUP v7.0. This time FORUM8 will distribute these 2 applications, LPILE Plus v5.0 and GROUP v7.0. Product overview is as following.

 LPILE Plus v5.0

LPILE Plus is a special-purpose program based on rational procedures for analyzing a pile under lateral loading.
The program computes deflection, shear, bending moment, and soil response with respect to depth in nonlinear soils. Components of the stiffness matrix at the pile head may be computed internally by the program to help the users in their super-structure analysis. Several pile lengths may be automatically checked by the program in order to help the user produce a design with an optimum pile penetration. Alternatively, the user can manually introduce other p-y curves. Special procedures are programmed for developing p-y curves for layered soils and for rocks. Several types of pile-head boundary conditions may be selected, and the properties of the pile can also vary as a function of depth. LPILE Plus has capabilities to compute the ultimate-moment capacity of a pile's section and can provide design information for rebar arrangement. The user may optionally ask the program to generate and take into account nonlinear values of flexural stiffness (EI) which are generated internally based on specified pile dimensions, material properties, and cracked/ uncracked concrete behavior.

Sample screen

p-y curve output example

LIST OF FEATURES
Five sets of boundary conditions are available to model the pile head: free head, pinned head with sway, fixed head with sway, or elastically-restrained with a rotational spring. Depending on boundary conditions, pile-head loading may consist of a lateral load, a bending moment, a specific lateral displacement, or a specific pile-head rotation. The ability to specify both deflection and rotation at the pile head is an useful feature available in LPILE Plus.
The user may optionally ask the program to generate and take into account nonlinear values of flexural stiffness (EI). These values are generated internally by the program based on cracked/uncracked concrete behavior and user-specified pile dimensions, and material properties. Version 5 allows the user to define multiple sections with nonlinear bending properties.
LPILE Plus model of soil response


Sample results from push-over analyses
Up to ten different load cases may be applied at the pile headin a single analytical run. This is a helpful feature for the quickobservation of pile behavior subjected to specific increments of lateral loads, bending moments, lateral displacements, o rpile-head rotations.
A set of distributed lateral loading may be applied anywhere along the length of the pile. Loading may be specified as constant or varying linearly with depth.
Four values (Kyy, Kyθ, Kθy, and Kθθ) of a typical 6x6 matrix for foundation stiffness may be generated by the program for a range of loading. Values are helpful as nonlinear foundation models in superstructure analysis.
An user-specified curve may be used to model the additional shear resistance provided by the soil at the base of large-diameter drilled shafts and/or short piles.
LPILE Plus has the capability to perform push-over analyses and can study the pile behavior after the development of plastic hinges (yielding).
Several pile lengths can be automatically checked by the LPILE Plus program in order to help the user produce a design with an optimum pile penetration.
Soil-resistance (p-y) curves can be internally generated by the program for the following soils: soft clay, stiff clay with or without free water, sand (Reese et al), sand (API), silt (c-φsoils), liquefied sand, strong rock, and weak rock.

Example of Calculation Result
Users may optionally input their own soil-resistance (p-y) curves for certain soil depth
Sample set of curves of bending moment
versus depth for different lateral loads
A special subroutine effectively incorporates the infuence of layered soils.
User-defined multipliers are provided to increase or reduce the soil resistance (p-y curves) at any points along the length of the pile. This feature is used in seismic conditions to reduce the response of liquefied layers or to account for Group Effects.
Linear interpolation of bending stiffness is computed for piles with varying cross sections.
The Graphics menu contains quick observations of results contained in the output file (variations of pile deflection, bending moment, shear and soil resistance with pile depth). The user can customized charts to prepare various engineering plots in high quality for presentation and report.


 GROUP v7.0

A Progam for the Analysis of Pile in a Group

GROUP has been well accepted as a valuable design tool for analyzing the behavior of pile in a group subjected to both axial and lateral loadings. The program computes the distribution of loads (combination of vertical, lateral, and overturning moment in up to three orthogonal axes) from the pile cap to piles arranged in a group. The piles may be installed vertically or on a batter and therir heads may be fixed, pinned, or elastically restrained by the pile cap. The program wil generate internally the nonlinear response of the soil, in the form of t-z and q-q curves for axial loading, in the form of p-y curves for lateral loading. The p-y, t-z q-w and t-r curves may be generated internally ,emplyoing recommnendations in technical literature, or may be entered manually by the user. The pile-head forces and movements are introduced into equations that yield the behavior of the pile group in a grobal coordinate system. The program can internally compute the deflection, bending moment, shear, and soil resistance as a function of depth for each pile.

3D model with GROUP V7.0

3-dimensional calculation


LIST OF FEATURES
Three boundary conditions are available for pile-head connections to the rigid cap: pinned, fixed, or elastically restrained.
p-y curves may be input by the user or may be automatically generated by the program and printed for review.
This program can provide data for evaluating the pile-cap stiffness, often uesd by structural engineers for foundation simulation in ther numerical models.
The graphical observation of output curves features a new interface that allows zooming of areas of particular interest. The user may thus observe the detailed behavioral measurements of any portion of the depth of each pile sub-group.
The type and number of graphs generated by GROUP v7.0 have been increased over previous versions.
More importantly, the program plots the force and displacement on the pile cap, such as the axial force (tension and compression) of each pile on the pile cap, llateral forces (shear and moment) of each pile on the pile cap, and the displacement of the pile cap in different directions.
The program allows for up to 2000 piles in a group, and each pile can have diffrent EI values in orthogonal directions.
The program will consider the nonlinear bending stiffness(EI) of each pile during computation. The user can enter nonlinear moment-curvature curves under different axial loads for each pile.


Program GROUP allows the input of groups of straight or batter piles, layered soil profiles, various cross-section of pile sub-groups, and several loading arragements

Sample windows used for data input


Moment distribution


Moment distribution


Moment distribution


Moment distribution

Products name Price
LPILE Plus 5 for Windows (A Program for the Analysis of Pile and Drilled Shafts Under Lateral Loads) ¥130,000 (tax excluded)
GROUP 7.0 (3-D) for Windows (A Program for the Analysis of Piles in a Group) ¥200,000 (tax excluded)


Developed by ENSOF, INC.. : www.ensoftinc.com


(UP&Coming 2008 New Year Special issue)

FORUM8