# Pipe Pile

Pipe piles are either a welded or seamless-steel pipe which may be driven either open-ended or closed-ended.

## Pile foundations

Ruwan Rajapakse PE, CCM, CCE, AVS, in Geotechnical Engineering Calculations and Rules of Thumb (Second Edition), 2016

### 40.5Pipe piles

Pipe piles are available in many sizes, and 12-inch diameter pipe piles have a range of thicknesses.

Pipe piles can be driven either open end or closed end. When driven open end, the pipe is cleaned with a jet of water.

#### 40.5.1Closed end pipe piles

Closed end pipe piles are constructed by covering the bottom of the pile with a steel plate (Figure 40.10).

In most cases, pipe piles are filled with concrete. In some cases, pipe piles are not filled with concrete to reduce the cost. If pipe piles were not filled with concrete, then corrosion protection layer should be applied.

If a concrete filled pipe pile is corroded, most of the load carrying capacity of the pile would remain intact due to concrete. On the other hand, an empty pipe pile would lose a significant amount of its load carrying capacity.

Pipe piles are a good candidate for batter piles.

Structural capacity of pipe piles is calculated based on concrete strength and steel strength. The thickness of the steel should be reduced to account for corrosion (typically reduced by 1/16 in. to account for corrosion).

A pipe pile is covered with an end cap. The end cap is welded as shown in Plates 40.4–40.8.

In the case of closed-end driving, soil heave can occur. There are occasions where open end piles also generate soil heave. This is due to plugging of the open end of the pile with soil.

Pipe piles are cheaper than steel H-piles or concrete piles.

#### 40.5.2Open End Pipe Piles

Open end pipe piles are driven and soil inside the pile is removed by a water jet (Figure 40.11).

Open end pipe piles are easier to drive through hard soils than closed end pipe piles (Figure 40.12).

#### 40.5.3Ideal situations for open end pipe piles

A soft layer of soil followed by a dense layer of soil (Figure 40.13).

Medium dense layer of soil followed by a dense layer of soil (Figure 40.14).

#### 40.5.4Telescoping

Figure 40.15 shows telescoping to improve driving ability.

Due to the smaller diameter of the telescoping pipe pile, the end bearing capacity of the pile would reduce. To accommodate the loss, the length of the telescoping pile should be increased.

#### 40.5.5Splicing of pipe piles

Pipe piles are spliced by fitting a sleeve. The sleeve would fit into the bottom section of the pile as well as the top section (Figure 40.16).

URL: https://www.sciencedirect.com/science/article/pii/B9780128046982000404

## Bridge foundations

V. Modeer, R.K. Bharil, in Innovative Bridge Design Handbook (Second Edition), 2022

### 6.1.2Steel pipe piles

Pipe piles can be fabricated as extruded or rolled thin-walled pipe piles, spiral welded steel, extruded steel, and rolled steel (ASTM A252, Standard Specification for Welded and Seamless Steel Pipe Piles). The available size range of pipe piles and the stiffness that can be enhanced by increasing the pipe wall thickness has made pile piles desirable for major bridge foundations. Pipe piles can also be driven with a closed end and filled with reinforced concrete as a structural element. Depending on location, the steel wall’s corrosion can be a concern and should be accounted for in sizing the pipe. Typically, pipe piles greater than 1 m in diameter are open-ended. Driving very large 3 m and larger-diameter piles became possible as a result of the offshore foundation construction (Figures 25.5–25.7). Pile-driving equipment also became available for these piles as a result of the need to drive large piles for the offshore industry. There is a likelihood that thin-walled pipe piles used for friction and end bearing could be damaged during the driving if the pile and hammer system are not appropriately matched. Wave equation analyses should be performed for thin-walled pipe pile driving to determine driving stresses for a given pile-and-hammer system in a given soil profile.

URL: https://www.sciencedirect.com/science/article/pii/B9780128235508000020

## Bitumen-coated pile design

Ruwan Rajapakse, in Pile Design and Construction Rules of Thumb (Second Edition), 2016

### 16.7Case study: bitumen-coated piles

#### 16.7.124″ pipe piles

Concrete-filled pipe piles were used to support the abutment. These piles were extended to the bedrock. Initial calculations were done to investigate the possibility of ending the piles in the sand layer. The settlements were found to be too large if they were to be ended in the sand layer. The capacity of the piles was estimated to be 150 tons per pile (Fig. 16.10).

#### 16.7.2Why pipe piles

The clay layer would undergo settlement due to the fill above. When the clay layer settles, it would carry the piles down with it creating negative skin friction (downdrag) on piles. The negative skin friction forces could be as high as 100 tons per pile. The capacity of the piles is not more than 150 tons per pile. The effective capacity (the capacity that is useful) of the pile will be 50 tons per pile. This is not economical. A bitumen coating (1/8″ thick) was used to reduce the downdrag. Bitumen-coated piles were placed on bored holes. Holes were bored and the piles were placed inside the hole.

Note: H-piles have lesser perimeter area compared to similar pipe piles. Hence, H-piles would have less downdrag. On the other hand, H-piles are much more expensive than pipe piles (without bitumen coating). A cost comparison between bitumen-coated pipe piles and H-piles was done and bitumen-coated pipe piles were selected.

URL: https://www.sciencedirect.com/science/article/pii/B9780128042021000164

## Design of driven piles

Ruwan Rajapakse, in Pile Design and Construction Rules of Thumb (Second Edition), 2016

### 8.6Recommended guidelines for pile design

American Society of Civil Engineers(ASCE) has provided the following guidelines for pile foundation design (ASCE, 1997):

#### 8.6.1Steel piles

Steel pipe piles should have a minimum yield strength not less than 35,000 psi.

Structural steel piles should conform to ASTM A36, ASTM A572, and ASTM A588.

Steel pipe piles should conform to ASTM A252.

Steel-encased cast-in situ concrete piles should conform to ASTM A252, ASTM A283, ASTM A569, ASTM A570, or ASTM A611.

The allowable design stress in steel should not be more than 35% of the minimum yield strength of steel.

#### 8.6.2Minimum dimensions for steel pipe piles

Pipe piles should have a minimum outer diameter of 8 in.

Minimum wall thickness of 0.25 in. is recommended for pipe diameters of 14 in or less. Minimum wall thickness of 0.375 in. is recommended for pipe diameters greater than 14 in.

Steel pipe piles with lesser wall thickness are allowed when the pipe piles are filled with concrete.

#### 8.6.3Concrete piles

##### 8.6.3.1Reinforced precast concrete piles

Diameter or minimum dimension measured through the center should not be less than 8 in.

Minimum 28 day concrete strength (fc′) = 4,000 psi.

Minimum yield strength of rebars = 40,000 psi.

The allowable design stress in concrete should not be more than 1/3 of the minimum concrete strength.

The allowable design stress in steel should not be more than 40% of the minimum yield strength of steel.

##### 8.6.3.2Prestressed concrete piles

Diameter or minimum dimension measured through the center should not be less than 8 in.

Minimum 28 day concrete strength = 4,000 psi.

Minimum yield strength of rebars = 40,000 psi.

The effective prestress should not be less than 700 psi.

The allowable axial design compressive stress applied to the full cross-section should not exceed 33% of the specified minimum concrete strength minus 27% of the effective prestressed force.

##### 8.6.3.3Concrete filled shell piles

Diameter or minimum dimension measured through the center should not be less than 8 in.

Minimum 28 day concrete strength = 3,000 psi.

Minimum yield strength of re-bars = 40,000 psi.

Thin shells less than 0.1 in. thick should not be considered as load-carrying members.

The allowable design stress in concrete should not be more than 1/3 of the minimum concrete strength.

The allowable design stress in steel should not be more than 40% of the minimum yield strength of steel.

##### 8.6.3.4Augered pressure-grouted concrete piles

Diameter should not be less than 8 in.

Minimum 28 day concrete strength (fc′) = 3,000 psi.

Minimum yield strength of rebars = 40,000 psi.

The allowable design stress in concrete should not be more than 1/3 of the minimum concrete strength.

The allowable design stress in steel should not be more than 40% of the minimum yield strength of steel.

##### 8.6.3.5Maximum driving stress

Maximum driving stress for steel piles = 0.9 fy (for both tension and compression): fy = yield strength.

Maximum driving stress for timber piles = 2.5 × (z) (here, z = allowable design strength of timber piles).

Maximum driving stress for precast concrete piles = 0.85 fc′ for compression; = 3(fc′)1/2 for tension; fc′ = 28 day concrete strength

Maximum driving stress for prestressed concrete piles = (0.85fc′ − fpe) for compression (fpe = effective prestress, force).

Maximum driving stress for prestressed concrete piles = (3(fc′)1/2 + fpe) for tension (fpe = effective prestress force).

URL: https://www.sciencedirect.com/science/article/pii/B9780128042021000085

## Geotechnical data and piles design

Mohamed A. El-Reedy Ph.D., in Marine Structural Design Calculations, 2015

### Example 6.7

Calculate the composite pipe pile of Figure 6.22, where the actual moment of inertia is described as follows:

Do1=1800 mm

Di1=1730 mm

Do2=1600 mm

Di2=1540 mm

I1=π[(Do1)4 – (Di1)4]/64=7,5601,916,209 mm4

I2=45,607,749,335

It=I1+I2=1.2121×1011 mm4

A1=π[(Do1)2 – (Di1)2]/4=194,071.8862 mm2

A2=147,969.014 mm2

AG=339,998.8649 mm2

The equivalent composite pile is

I=1.2121×1011 mm4

Do=1800 mm

Di={[I (64)/π] – ( Do)4}0.25=1683.28 mm

t=DoDi=58.36 mm

Area=π[(Do1)2 – (Di1)2]/4= 319,317.75 mm2

Elastic modulus for steel, Es=210,000 MPa

Elastic modulus for grout, EG=30,000 MPa

Et={Es [(Do1)2−(Di1)2]+Es (Do2)2−(Di2)2}+EG [(Di1)2−(Do2)2]/Do=32,235 MPa

URL: https://www.sciencedirect.com/science/article/pii/B9780080999876000064

## Design, construction and installation of support structures for offshore wind energy systems

K. Lesny, W. Richwien, in Wind Energy Systems, 2011

### Monopiles

Monopiles are usually steel pipe piles (see Fig. 16.2). They extend above the water level where the tower is connected with a so-called transition piece (see section 16.5.1).

Up to now monopiles have only been installed in water depths up to about 25 m with correspondingly moderate wave loading. Deeper water and the accompanying increase in loading, as well as higher performance wind turbines, directly result in greater diameters and embedment lengths of a monopile and may lead to uneconomic and technically unfavourable design solutions.

URL: https://www.sciencedirect.com/science/article/pii/B9781845695804500168

## Geotechnical Data and Pile Design

Mohamed A. El-Reedy Ph.D., in Offshore Structures, 2012

### Skin Friction and End Bearing in Cohesive Soils

Traditionally, piles for an offshore structure platform are pipe pile. If the pipe pile penetrates cohesive soils, the shaft friction, f (in kPa), at any point along the pile may be calculated by:

(4.14)$f=\alpha c$

where α = a dimensionless factor and c = undrained shear strength of the soil at the point in question.

The factor α can be computed by:

(4.15)$\begin{array}{ll}\alpha \hfill & =0.5\psi -0.5\psi \le 1.0\hfill \\ \alpha \hfill & =0.5\psi -0.25\psi >1.0\hfill \end{array}$

with the constraint that α ≤1.0, where ψ = c/p, for the point in question and p′ is the effective overburden pressure at the point in question (in kPa). For underconsolidated clays, clays with excess pore pressures undergoing active consolidation, α can usually be taken as 1.0.

The appropriate methods for determining the undrained shear strength, c, and effective overburden pressure, p′, including the effects of various sampling and testing procedures, are important. As the number of pile-load tests is not enough in soils having c/p′ ratios greater than three, Equation (4.15) should be applied with some engineering judgment for high c/p′ values. The same engineering judgment should be applied for deep-penetrating piles in soils with high undrained shear strength, c, where the computed shaft frictions, f, using Equation 4.14 above, are generally higher than previously specified in API RP2A. In the case of very long piles, some reduction in pile capacity occurs, because the shaft friction may reduce to some lesser residual value on continued displacement.

For piles end bearing in cohesive soils, the unit end bearing, q (in kPa), may be computed by:

(4.16)$q=9c$

It is obvious that in open-driven piles the shaft friction, f, acts on both the inside and outside of the pile. The total resistance is the sum of the external shaft friction, the end bearing on the pile wall annulus and the total internal shaft friction or the end bearing of the plug, whichever is less.

If the pipe pile is considered to be plugged, the bearing pressure may be assumed to act over the whole cross-section of the pile. For unplugged piles, the bearing pressure will be calculated on the pile wall annulus only. Whether a pile is considered plugged or unplugged may be based on static calculations. For example, a pile could be driven in an unplugged condition but act plugged under static loading.

In some cases, piles are driven in undersized drilled holes, piles are jetted in place or (in some minor projects) the piles are drilled and grouted in place. In these situations, the soil disturbance resulting from installation will affect the shaft friction values. In general, f should not exceed values for driven piles; however, in some cases for drilled and grouted piles in overconsolidated clay, f may exceed these values.

In determining f for drilled and grouted piles, the strength of the soil-grout interface, including potential effects of drilling mud, should be considered. As discussed by Kraft and Lyons (1974), a further investigation and check should be made of the allowable bond stress between the pile steel and the grout.

The shaft friction values, f, in the cohesive layers should be as given in Equation (4.14). End-bearing values for piles tipped in cohesive layers with adjacent weaker layers may be as given in Equation (4.16), assuming that the pile achieves penetration of two to three pile diameters or more into the layer in question and the tip is approximately three pile diameters above the bottom of the layer, to avoid punch through.

Some modification in the end-bearing resistance may be necessary if these distances are not achieved.

URL: https://www.sciencedirect.com/science/article/pii/B9780123854759000043

## Applications of PCC Piles for Highway and High-Speed Railway Construction in China

Han-long Liu, in Ground Improvement Case Histories, 2015

### 22.2.2Construction method

Cast-in-situ, rather than precast concrete pipe piles, are used. This is because it is difficult to transport and install large diameter precast pipe piles without affecting the integrity of the pile, particularly when the piles are not reinforced. As the PCC pipe pile is intended to be used mainly for improving the bearing capacity and reducing the settlement of soft ground, it would be possible to jack in casings to cast the concrete pile in situ. For this purpose, a special pile driving machine, a PCC piling machine, was designed to install the PCC pipe (Liu et al., 2003a). A picture of the piling machine in action is shown in Fig. 22.1. An annular steel casing that is made of two coaxial steel tubes is used as a form to case the hollow pile. The annular casing is closed ended. A cutting shoe made of steel plates, as shown in Fig. 22.2, is used to close the end. To facilitate installation, the inner and outer tubes are staggered to form a cutting edge of 30° (see Fig. 22.2). The diameter of the outer casing and the nominal diameter of the pipe pile ranges from 1.0–1.5 m. The diameter of the inner casing is chosen to be 200–300 mm smaller than the outer casing so the wall thickness of the pipe pile can be controlled between 100 and 150 mm.

The PCC pile installation sequence is shown in Fig. 22.3. The annular casing is first erected on the PCC piling machine (Fig. 22.3(a)) and is initially pushed and then vibro-driven into the ground (Fig. 22.3(b)). The rate of jacking is dependent on the ground conditions. The length of the piles depends on the design requirement. After the casing reaches the desired depth, concrete is poured into the annular of the casing (Fig. 22.3(c)). The slump ratio of the concrete is controlled within 50–100 mm. After this, the steel casing is withdrawn from the ground by vibro means (Fig. 22.3(d)). When the casing is being pulled up, the plates that seal the tip of the casing (shown in Fig. 22.2) will be open.

The standard withdrawal procedure has been stipulated in Technical Specification, JGJ/T213 (2010). It requires the withdrawing rate to be controlled within 1.0–1.2 m/min under normal circumstances. However, a slower rate of 0.6–0.8 m/min should be used for loose to medium loose sand layer. The casing should vibrate for 10 sec before withdrawal. Subsequently for every 1 m withdrawal, the pulling should be stopped temporarily to vibrate the casing for 5–10 sec until the casing is completely withdrawn. The vibratory effect applied to the casings during withdrawing also helps the concrete to be compacted. The maximum depth of the PCC pile is controlled by the height of the PCC piling machine and is normally within 25 m. If piles longer than the height of the piling machine are used, welding of casings is required. This will reduce the installation speed. When necessary, a circular steel reinforcement cage can also be used to reinforce the top part or the entire length of the pile. When the casing is removed, the top 0.5 m soil inside the PCC pile is excavated and filled with lean concrete to form a pile cap.

URL: https://www.sciencedirect.com/science/article/pii/B9780081001929000223

## CPT and CPTu for foundation settlement and load–displacement (P-Δ) estimation

Abolfazl Eslami, ... Mohammad M. Eslami, in Piezocone and Cone Penetration Test (CPTu and CPT) Applications in Foundation Engineering, 2020

### 8.7.1First case study: short driven steel pile (9m long)

Example 8.2

The steel closed-ended pipe pile with 355 mm wide and 9 m long is investigated. The pile is under 1MN loading (800 kN dead load and 200 kN live load). The CPT profile of the site is shown in Fig. 8.9, and the load–displacement curve of the pile is illustrated in Fig. 8.10.

The step-by-step procedure to predict the load–transfer curves and load–displacement of pile using the analytical–numerical approach proposed by Valikhah et al. (2018) is as below:

The geometric mean of qc in the influenced zone (4b below and 8b above the pile tip): 7 MPa.

The geometric mean of fs along the pile length: 25 kPa.

Unit weight from Mayne (2001) equation: γt = 12 + 1.5(ln(fs+1)) = 16.89 kPa.

The effective stress at the pile tip level: σ0 = 2×16.89 + 7×6.89 = 82.01 kPa

${a}_{t}=0.0009\phantom{\rule{0.25em}{0ex}}\mathrm{ln}\frac{1}{\left(\frac{{q}_{c}}{{\sigma }_{0}}\right)}+0.0067=0.0009\phantom{\rule{0.25em}{0ex}}\mathrm{ln}\frac{1}{\left(\frac{7000}{82}\right)}+0.0067=0.0027$
${b}_{t}=\frac{0.002}{\sqrt{{\sigma }_{0}}}=\frac{0.002}{\sqrt{82}}=0.00022$
${a}_{s}=0.0017{e}^{\left(\frac{97.7}{{f}_{s}}\right)}=0.0017{e}^{\left(\frac{97.7}{25}\right)}=0.085$
${b}_{s}=0.0242{\left(\frac{1}{{f}_{s}}\right)}^{0.038}=0.0242{\left(\frac{1}{25}\right)}^{0.038}=0.021$

Friction ratio:

$a=\frac{0.006}{{\left(\frac{{q}_{c}}{{\sigma }_{0}}\right)}^{0.4}}=\frac{0.006}{{\left(\frac{7000}{82}\right)}^{0.4}}=0.001$
$b=\frac{0.089{R}_{f}}{B}=\frac{0.089×0.0036}{0.355}=0.0009$

Using the obtained parameters and Eqs. (8.17)–(8.19), tz, qz, and PΔ curves. The results obtained by the proposed approach are shown in Fig. 8.11. Although the proposed approach by Valikhah et al. (2018) is not able to predict the softening behavior of the piles, as shown in the figure, the results are not far from the actual behavior of pile and are in acceptable agreement with the measured load–displacement curve for the piles.

URL: https://www.sciencedirect.com/science/article/pii/B9780081027660000080

## Uncertainty and reliability in foundation engineering

Abolfazl Eslami, ... Mohammad M. Eslami, in Piezocone and Cone Penetration Test (CPTu and CPT) Applications in Foundation Engineering, 2020

### 11.5.1Case study No. 5: application of the proposed algorithm/practical application of the proposed algorithm

Shamshirgaran and Ebrahimian (2018) investigated different design methods for an open-ended steel pipe pile (embedment length = 88 m and diameter = 1.5 m). The result of CPTu, done in vicinity of the pile, is shown in Fig. 11.22. The pile was driven into a clayey soil. By searching in the compiled data bank, a pile, TOKYO PORT2, was found in a close condition of either shape, size, embedment length, and soil to this pile.

Based on the analyses, methods such as UniCone (Eslami and Fellenius, 1997), Modified UniCone (Niazi and Mayne, 2016), ICP (Jardine et al., 2005), Meyerhof (1976, 1983), Dutch (De Ruiter and Beringen, 1979), and German (Kempfert and Becker, 2010) perform better than other investigated methods. The result of different predictive methods is presented in Table 11.8. As shown, for long-term capacity methods such as UniCone, Modified UniCone and Dutch result in better estimation of actual axial-bearing capacity.