Wutec Geotechnical International - Design, Application of Geotechnical Software

Geotechnical calculation online library is created to provide geotechnical engineers easily accessible and reliable solutions to some of the most common geotechnical problems including ground settlements from one-dimensional soil consolidation (stresses calculated using the Boussinesq's equation), finite element solutions of the Terzaghi's consolidation equation, static Coulomb's and dynamic Mononobe-Okabe soil pressure coefficients, simple design calculation for mechanically stabilized earth structures, lock block retaining walls, and others. This library is developed under the supervision of Dr. Guoxi Wu, Ph.D., P.Eng. of BC, Canada

All calculations, including the finite element consolidation analysis, are carried out on the web server. A computer is not required to run the program; instead only an Internet browser is needed to setup input and display results.

WickDrain provides a simplified calculation of consolidation time for vertical drains. The calculation employs Barron's equation which only requires three input parameters, i.e., diameter of vertical drains, diameter of vertical drain influence zone, and coefficient of consolidation for drainage in horizontal direction.

Consolidation Settlement provides calculations of consolidation induced settlements of clayey soils in a multi-layer column. Each layer can have its own unique soil properties including total unit weight, initial void ratio, compression index Cc and recompression index Cr. The preconsolidation pressure (sp’) can be assigned a constant value or as a ratio of the initial effective vertical stress for each layer. Settlement at any location, expressed by X and Y coordinate, under multi-zones of loading can be calculated. The incremental vertical stresses under the point of interest are computed using the Boussinesq's equation and the method of superposition for the multi-zones of loads. Once the ground water level is specified by the user, the program automatically computes the initial effective vertical stress for each soil layer, including sublayers . A soil layer is divided automatically by the program into many sublayers as desired by the user in order to increase the accuracy of calculation. Finally the program computes the primary consolidation settlement for underconsolidated soil (OCR<1), or normally consolidated soil(OCR=1), or overconsolidated soil (OCR>1). Secondary compression settlement can also be computed.

Consolidation analysis provides finite element solutions of the Terzaghi's consolidation equation in multi-layer column. This calculation is a continuation of Consolidation Settlement , which compute stresses in soils using the Boussinesq's equation for multi-zones of loading and calculate consolidation induced settlement of clayey soils. Each soil layer can have its own unique coefficient of consolidation (Cv), and the drainage conditions at the bottom of each layer are specified while the top (zero depth) of the column is assumed to be free drained. In the analysis the pore water pressure at t=0 is assumed to be the same as the incremental stresses carried over from Consolidation Settlement. The Terzaghi’s 1D consolidation equation is solved using the finite element method. The results of analysis include settlements of each soil layer and sublayer for up to 4 specific points of time, as well as a complete curve of settlement versus time for up to 4 specific locations (sublayer) in the soil column.

Soil Pressure Coefficient (Ka, Kp) provides calculation of later earth pressure coefficients for cohesionless soils (sandy soils) , including Coulomb's active and passive coefficients under static conditions, and Mononobe-Okabe active and passive soil pressure coefficients under seismic loading. Base input parameters include soil friction angle (phi), back slope angle (i), wall-soil interface friction angle, wall inclination angle (beta), and horizontal and vertical seismic coefficient (kh and kv). Total amount of lateral force on a retaining wall is also computed with a specified wall height and the unit weight of the backfill.

Anchorage Wall provides design calculation of an anchored retaining wall including external global stability (factors of safety on sliding, over-turning and bearing), and internal anchor stability (factors of safety on anchor yield and anchor pullout). Base input parameters include anchor length, anchor vertical and horizontal spacing, dip-down angle, anchor yield force, anchor-grout-soil bonding coefficient, and backfill soil unit weight and lateral pressure coefficients (Ka or Kae), which may be obtained in advance using (Ka, Kp). In addition to a triangle distribution of lateral soil pressure, the calculation module also allows for a trapezoid distribution especially for simulation of seismic soil pressure where soil pressure is non-zero at the wall top. The web page includes an easy-to-understand force diagram for the anchored wall, and all equations used in the calculation can be downloaded on the web page through the tab “Download Calculation Note”.

MSE Wall provides design calculation of a mechanically stabilized earth retaining wall including external global stability (factors of safety on sliding, over-turning and bearing), and internal reinforcement stability (factors of safety on rupture and pullout). Base input parameters include reinforcement length (assumed to be horizontal), vertical arrangement, reinforcement tensile/rupture load capacity, soil/reinforcement frictional coefficient, and backfill soil unit weight and lateral pressure coefficients (Ka or Kae), which may be obtained in advance using (Ka, Kp). In addition to a triangle distribution of lateral soil pressure, the calculation module also allows for a trapezoid distribution especially for simulation of seismic soil pressure where soil pressure is non-zero at the wall top. The web page includes an easy-to-understand force diagram for the MSE wall, and all equations used in the calculation can be downloaded on the web page through the tab “Download Calculation Note”.

Segmental Block Wall provides design calculation of a segmental block retaining wall, including factors of safety on sliding and overturning for each block on the wall. Maximum pressure at the base of each block is calculated using two methods, i.e., the Meyerhof method and the method assuming a triangular distribution of base reaction. Base input parameters include size/weight of blocks and its arrangement, inter-block friction angle and base friction angle, wall/soil friction, wall inclination angle, and backfill soil unit weight and lateral pressure coefficients (Ka or Kae), which may be obtained in advance using (Ka, Kp). In addition to a triangle distribution of lateral soil pressure, the calculation module also allows for a trapezoid distribution especially for simulation of seismic soil pressure where soil pressure is non-zero at the wall top. The web page includes an easy-to-understand force diagram for the segmental block wall, and all equations used in the calculation can be downloaded on the web page through the tab “Download Calculation Note”.

Geotechnical Calculation Models