Tel: 1-206-279-3300

DeepEX 2020

Solving Deep Excavation Design

DeepEX 2017 talk to it and design your deep excavation!

Deep Foundation Software, Pile Rafts, Pile Groups

From soil estimation to axial and lateral pile capacity

DeepFND - Deep Foundation Software, caissons, CFA, drilled piles, driven piles, concrete, timber

From soil estimation to helical pile settlement estimation.

New helical pile software HelixPile

Excavations in 3D, VR, AR

Holographic model of a deep excavation with HoloDeepEX

Get the Free 3D Viewer

______________________

Free 45 min webinar

Deep Excavation Design

Fully booked!

Free Helical Pile Design Webinars:

To be announced

2-Day Deep Excavation and Soil nail wall design Workshop

16 PDH @ Plano, TX

Sep 30, Oct 1st, 2019

Only 1 spot left!

Renaissance Hotel, Legacy West

Renaissance Hotel Plano Legacy West

Early registration ends soon!

Signup for a free trial and get our free pdf on the five most common errors in deep excavation design
What do you want to design?
DeepFND 2020: Deep Foundation software (NEW: Pile-Group/Pile Raft Analysis!)
DeepEX 2020: Deep Excavation software
Soldier pile walls
Sheet pile walls
Secant pile Walls
Tangent piles
Diaphragm Walls
Soldier and Tremied Concrete
Soil Mix walls
Combined king pile sheet piles
Slope stability
Cost estimation for braced excavations
Waler-Strut Cofferdams
Snail-Plus 2019: Soil nailing - soil nailing walls
SiteMaster: Inclinometer software (adopted by Geokon)
HelixPile: Helical Pile Software
RC-Solver: Concrete Design ACI-318, EC2, EC8
Steel-Beam: Steel beam column design, full equations, AISC, EC3

Top down excavation, SI units

A. Project description

In this example we will design a 7 m top down excavation between two diaphragm walls supported by slabs and tieback supports. Tables 1 and 2 present the soil properties and the stratigraphy respectively. Table 3 presents the external loads. Table 4 presents the wall properties. Tables 5a and 5b presents the support properties. The ground elevation next to the wall is 0 m. The ground surface is inclined on both directions outside the walls. The general water elevation is -6 m.

Table 1: Soil properties

Name

Soil Type

Φ'

(deg)

c'

(kPa)

Su

(kPa)

γt

(KN/m3)

γdry

(KN/m3)

Kx

(m/sec)

Kz

(m/sec)

Eload

(kPa)

Eur

(kPa)

qskin,u

(kPa)

F

Sand

30

0

-

20

19

0.0001

0.0001

15000

45000

49.7

O1

Clay

22

2

20

16.5

14

10-7

10-7

2874

8622

35.2

Clay

Clay

28

0

150

20

19

10-10

10-10

20000

60000

180

Rock

Rock

30

100

-

27

25

0.0001

0.0001

479000

1437000

700

Table 2: Stratigraphy (Boreholes)

Soil Layer Name

Top Elevation (m)

OCR

Ko

F

0

1

0.5

O1

-4

1

0.562

Clay

-8

1

0.5

Rock

-16

1

0.5

Table 3: External loads

Name

Type

Position

(X0,Z0)

(X1,Z1)

Q0

Q1

0

Surcharge

On the ground

(-15,4.87)

(-4,1.3)

10 kPa

10 kPa

1

Moment

On the wall

(0.5,0)

-

-30 KNm/m

-

2

Moment

On the wall

(18.5,0)

-

35 KNm/m

-

Table 4: Wall properties

Type

Diaphragm (slurry) wall

Concrete

C20/25

Steel

S410

Top Elevation (m)

0

Height (m)

10

Thickness (m)

0.6

Hor. Spacing (m)

1

N of top rebars

9

Top bars #

D25

N of bottom rebars

9

Bottom bars #

D25

Shear reinf. #

D12

Shear reinf. hor. Spacing, Sh (cm)

25

Shear reinf. ver. Spacing, Sv (cm)

25

Table 5a: Tieback support properties

Name

Type

Elevation on the wall (m)

Angle (deg)

Free length (m)

Fixed length

(m)

Hor. Spacing

(m)

Prestress

(KN)

Section

1

Tieback

-1.5

30

15

10

3

150

6 Strands (1.334 cm diameter each)

2

Tieback

-1.5

150

15

10

3

150

6 Strands (1.334 cm diameter each)

4

Tieback

-4.5

30

15

10

3

150

6 Strands (1.334 cm diameter each)

5

Tieback

-4.5

150

15

10

3

150

6 Strands (1.334 cm diameter each)

Table 5b: Slab support properties

Name

Type

Elevation on the wall (m)

Concrete

Rebar steel

Slab Thickness (cm)

N. of Top rebars

Top bars Section

N. of Bottom rebars

Bottom bars Section

0

Slab

-0.2

C20/25

S500

40

12

D18

12

D18

3

Slab

-7.2

C20/25

S500

40

12

D18

12

D18

B. Modeling with DeepEX

B1. Use of DeepEX

Figure 1: Edit soil properties dialog.

Figure 2: Edit soil layers dialog.

Figure 3: Edit wall properties dialog.

Figure 4: Wall data dialog

Figure 5: Support options.

After drawing the support on the model, the Edit support data dialog appears (i.e. for tieback supports, Figure 6).

Figure 6: Edit support data dialog.

Figure 7: Load options.

After drawing the load on the model, the Edit surcharge dialog appears (i.e. for sitrip surcharges, Figure 8).

Figure 8: Edit distributed load dialog.

Figure 9: Surface options.

Figure10: Water elevation – settings.

With the draw custom water surface tool, we can draw a non-horizontal groundwater table. To do this, select this option and then start clicking the left mouse button from left to right (press enter to complete). To delete the custom water line, move on top in the model and press delete.

The draw a U line tool is used to draw a line of constant pore pressure in the model. This line is only used in slope stability analysis.

The define user water pressures tool launches the dialog for defining custom values of water pressures next to the walls. Please note that in the non-linear engine, two consecutive zero values of water pressure still count in increasing the total vertical stress by γw (see theory manual).

Figure 11: Ground water table.

B2. Example simulation

In DeepEX 2014 we can design our projects using construction stages. After the model is designed, the software calculates each construction stage, reassuring that the model is stable, since the last stage is not always the critical one. Next, we provide the steps in each construction stage, in order to simulate the project in DeepEX.

  1. Define the soil properties

  2. Define the soil layers (stratigraphy)

  3. Define the wall section and wall properties

  4. Define the slope surfaces

Figure 12: Model, Stage 0.

1. Excavate between the two walls to elevation -0.4 m.

1. Apply first slab support at elevation -0.2 m.

1. Excavate between the two walls to elevation -2 m.

1. Apply tiebacks on both sides of the walls at elevation -1.5 m.

Figure 13: Model, Stage 4.

1. Excavate between the two walls to elevation -5 m.

1. Apply tiebacks on both sides of the walls at elevation -4.5 m.

1. Excavate between the two walls to elevation -7.4 m.

1. Apply basement slab support at elevation -7.2 m

Figure 14: Model, Stage 8.

In DeepEX we can design several design sections in the same model. We can add new design sections as new or as copies of the existing ones, doing several modifications in the model, or just defining different standards, calculation or analysis methods.

C. Results in DeepEX

Since the model is ready, we can choose to calculate the design section, pressing on the button .

After the analysis is succeeded, the Summary table appears. Table 6 below includes some critical checks and values for each construction stage. Figures 15 to 18 present some graphical results from the results tab of DeepEX.

Table 6: DeepEX critical results/stage

Figure 15: Moment diagrams, Stage 7.

Figure 16: Shear diagrams, Stage 3.

Figure 17: Wall deflection diagrams, Stage 7.

Figure 18: Effective horizontal soil pressures, Stage 8.

Sign up for DeepEX to get the most out of your designs!

E-mail List Signup

Signup to our Email List for the latest information about our products, support and more.