GROUP is a well-accepted tool for analyzing the behavior of pile groups subjected to both axial and lateral loadings. The program was developed to compute the distribution of loads (vertical, lateral, and overturning moment up to three orthogonal axes) applied from any multiple locations in the pile cap to piles arranged in a group.

The program generates internally the nonlinear response of the soil, in the form of t-z and Q-w curves for axial loading, in the form of p-y curves for lateral loading and in the form of T-q curves for torsional loading. A solution requires iteration to accommodate the nonlinear response of each pile in the group model. Program GROUP solves the nonlinear response of each pile under combined loadings and assures compatibility of deformations and equilibrium of forces between the applied external loads and the reactions of each pile head.

Model the complex nonlinear soil behavior using well-known p-y, t-z, Q-w, and T-q curves from predefined list, or enter your own curves for the program to use. Some of the predefined p-y curves include submerged soft clay, stiff clay with and without free water, sand, silt, vuggy limestone, weak rock, stiff clay, and liquified sand.

Specify soil movement as lateral loading to pile groups with user-specified depth-displacement curves in two orthogonal lateral directions.

Model complex pile groups by combining combination of vertical and piles battered at arbitrary angles. Pile cross-sections can be constant or linearly varying along the depth of the pile, and can be rapidly generated from predefined lists or manually entered.

Consider material nonlinearity of piles by taking into account nonlinear values of flexural stiffness for individual or all piles.

Pile connections to pile heads may be modeled as either pinned, elastically restrained, or fixed for both orthogonal axes.

Specify user-defined p-y factors to reduce or increase soil resistance curves for individual piles or pile groups. These multipliers may be different in each orthogonal direction, and may vary along pile length.

Specify reduction factors on axial capacity of individual piles or pile groups as a whole for closely-spaced piles.

Apply three-dimensional point loads in any combination of forces and bending moments applied anywhere within the model.

Specify distributed lateral loads along lengths of piles. Soil movement can be specified as a lateral loading to the pile group with user-specified curves of displacement vs depth in the two orthogonal lateral directions. Predefined three-dimensional movements (displacement and rotations) can be manually specified to approximate equivalent forces for such conditions.

Compute the response of piles subjected to various different loading combinations.

Analyze and compute the deflection, bending moment, and shear forces along piles.

Generate pile-cap stiffness matrix to be used for approximating the stiffness of the foundations of superstructures supported by pile groups. The pile-cap stiffness matrix can be generated for any load condition.

Get results faster by taking advantage of the built-in distributed solver.

Plot the bending moment, shear force, deflection and more along the depth of piles.

Compare the results of different load cases.