# Analysis of Deep Foundations

Deep foundation problems that can be analyzed are, Figure 32:

1- Analysis of single pile

2- Bearing capacity and settlement of single pile or pile wall

3- Analysis of piled raft

4- Stress coefficient according to GEDDES

5- Sheet pile wall

6- Analysis of single barrette

7- Analysis of barrette raft

Figure 32 "Deep foundation problems"

- 1- Analysis of single pile
- 2- Bearing capacity and settlement of single pile or pile wall
- 3- Analysis of piled raft
- 4- Stress coefficient according to GEDDES
- 5- Sheet pile wall
- 6- Analysis of single barrette
- 7- Analysis of barrette raft

Linear and nonlinear analyses for piles can be carried out. Elastic pile is analyzed using the finite element method. Half space and layered soil models are considered, Figure 33 and Figure 35.

Figure 33 "Analysis of single pile"

Figure 34 "Analysis of single pile", Soil profile

Figure 35 Elastic and rigid displacement along the pile

Bearing capacity and settlement of single piles or pile walls according to DIN 4014 can be determined. The input data are dimensions of piles, pile tip resistance from penetration test or cohesion Cu of the layers. Skin friction of the pile can be defined by the user or determined according to DIN 4014, (Figure 36 to Figure 39)

Figure 36 "Bearing capacity and settlement of single pile or pile wall", Pile data

Figure 37 "Bearing capacity and settlement of single pile or pile wall", Skin friction part

Figure 38 "Bearing capacity and settlement of single pile or pile wall", End bearing part

Figure 39 Load settlement curve for pile according to DIN 4014

The settlement of groups of vertically loaded piles and rigid piled rafts on layered soil or half-space medium can be determined, (Figure 40 to Figure 47). The methods of soil analysis are:

- Linear analysis
- Nonlinear analysis using a hyperbolic function for load-settlement
- Nonlinear analysis using German standard DIN 4014 for load-settlement
- Nonlinear analysis using German recommendations EA-Piles for load-settlement (lower table values)
- Nonlinear analysis using German recommendations EA-Piles for load-settlement (upper table values)

Figure 40 "Analysis of piled raft"

Figure 41 "Analysis of piled raft", Pile geometry

Figure 42 "Analysis of piled raft", Pile cap

Figure 43 "Analysis of piled raft", Soil profile

Figure 44 System of loading

Figure 45 Pile location and groups

Figure 46 Contact pressure under the piled raft

Figure 47 Pile reactions of piled raft

Stresses coefficient due to a load under the surface according to GEDDES can be obtained in Figure 48 and Figure 49.

Three types of loading are considered:

- Stress coefficient for a point load.
- Stress coefficient for uniform skin friction.
- Stress coefficient for linear variation of skin friction.

Figure 48 "Stress coefficient according to GEDDES"

Figure 49 Stress coefficient according to GEDDES

The length of sheet pile can be determined for, Figure 50 to Figure 54:

- Cantilever sheet pile wall.
- Anchored sheet pile wall with free earth support.
- Anchored sheet pile wall with fixed earth support.

Figure 50 "Sheet pile wall"

Figure 51 "Sheet pile wall", Soil data

Figure 52 Earth pressure on the sheet pile

Figure 53 Moments on the sheet pile

Figure 54 Shear forces on the sheet pile

Linear and nonlinear analyses for barrettes can be carried out. Elastic barrette is analyzed using the finite element method. It is possible to analyze a single barrette under moments and loads in

*x*-,*y*- and*z*-directions on layered soil or half-space soil medium, (Figure 55 to Figure 59).Figure 55 "Analysis of single barrette"

Figure 56 "Analysis of single barrette", Soil profile

Figure 57 Elastic displacement along the barrette

Figure 58 Bending moment along the barrette

Figure 59 Load displacement curve of barrette

The settlement of groups of vertically loaded barrettes and rigid barrette rafts on layered soil or half-space medium can be determined, (Figure 60 to Figure 64). The analysis of barrette groups and barrette rafts can be carried out linearly or nonlinearly according to the following cases:

- Elastic barrette groups
- Rigid free-standing raft
- Rigid barrette raft foundation
- Elastic barrette raft foundation

Figure 60 "Analysis of barrette raft", Barrette data

Figure 61 "Analysis of barrette raft", Barrette geometry

Figure 62 "Analysis of barrette raft", Soil profile

Figure 63 "Analysis of barrette raft", Barrette cap

Figure 64 Settlements as contour lines