Drain Property

Define the Drain Properties for an Analysis Model.

Applicable Modules:

From the Main Menu, select 1D Consolidation > Property > Drain Property

From the Command Line, type 'DrainProperty' or 'DP'

Data

The drain properties entered are displayed. Select data to modify.

General

ID

ID numbers are sequentially assigned to the Drain Property data in the order of which it has been defined.

Name

Name of the Drain Property data.

Type

Select a drain type.

PBD

Plastic Board Drain is used to improve soft ground whose advantages are known for economy, ease of construction and quality management.

SCP

Sand Compaction Pile involves driving and vibrating closely-spaced sand columns into the soft ground forming compaction piles.

GCP

Gravel Compaction Pile involves driving and vibrating closely-spaced gravel columns into the soft ground forming compaction piles.

SD

Sand Drain involves drilling vertical holes into a cohesive soil and filling the holes with sand, which expels pore water to promote consolidation by reduced drainage distance.

Pack

Pack Drain, Polyethylene involves woven geotextile bag columns filled with sand compacted into the soft ground to promote consolidation drainage.

CD

Cylindrical Drain is vertically installed into a soft cohesive soil, which is a punched spiral pipe functioning as drain board. It promotes consolidation settlement by expelling pore water to the surface.    

Fiber

Fiber, outstanding for drainage effect, is vertically placed into the ground, which dewaters pore water to promote consolidation by reducing the drainage distance.

Recently more environment friendly natural fiber materials such as coconut fiber and burlap fabric have been used.

Array

Select a drainage layout in plan.

Triangular Arrangement

Refer to the diagram.

Rectangular Arrangement

Refer to the diagram.

Center to Center Spacing

Enter the drainage spacing.

Calculation Option

Method

Select a proposed theoretical equation for radial consolidation.

Hansbo

The average consolidation at a given depth is calculated when vertical drainage is installed reflecting smearing effect (ground disturbance) and well resistance (Drainage Resistance: Activated, Disturbance Effect: Activated).  

Barron

The average degree of consolidation over the total consolidation layers is calculated under the equal strain consolidation condition (Drainage Resistance: Deactivated, Disturbance Effect: Deactivated).

Yoshikuni

The proposed equation by Yoshikuni (1979) calculates the average degree of consolidation considering only the effect of drainage resistance (Drainage Resistance: Activated, Disturbance Effect: Deactivated).

Onoue

The equation is proposed by Onoue (1988), which can consider the effect of disturbance region and drainage resistance irrespective of permeability, on the basis of the use of the drainage resistance factor proposed by Yoshikuni and Nakamodo (1974) (Drainage Resistance: Activated, Disturbance Effect: Activated).

Drain Resistance

Drain Resistance considers the phenomenon for delayed consolidation due to the degradation of the flow-ability of vertical drainage as the consolidation progresses.    

Smear Effect

Disturbance Effect considers delayed consolidation due to the degradation of the coefficient of consolidation from soil disturbance.

Smear/Well Properties

Diameter (dw)

Enter the diameter of the drain. Use the transformed diameter in case of PBD.

Permeability (kw)

Coefficient of Permeability for the drainage.

Consolidation Coefficient Ratio (Cv/Ch)

The ratio of the coefficients of consolidation in the vertical direction to the horizontal direction.

Diameter of Smear Zone (ds)

Transformed diameter of the disturbed region.

Permeability Ratio of Smear Zone (Kh/Ks)

The ratio of the coefficients of permeability of the original ground in the horizontal direction to that of the disturbed region.

Section Information

Horizontal section of the drainage layout.

SCP / GCP Properties

Stress Sharing Ratio

Stress distribution ratio of complex ground.

Internal Friction Angle

Internal friction angle of SCP/GCP.

Unit Weight

Unit weight of SCP/GCP.

Saturated Unit Weight

Saturated unit weight of SCP/GCP.

Pack Drain

L1

Casting spacing of drainage in the longitudinal direction.

Click to add the property.

Click to modify an already defined property.

Click to delete the property.

Click to close the window.