Design and Load Testing of Large Diameter Open-Ended Driven Piles

The aim of this preliminary research is to study the accept tolerance of driven piles with position’s deviation. More than five thousand driven piles were installed in the approach bridge, which adopted two classes, i.e.Φ1.6m steel pipe pile and Φ1.0m spun pile. The original position acceptance criteria was deviation tolerance less than 75mm. This was not reasonable enough to take into account the marine construction conditions. According to a detailed comparison of the existed different standards and simplified calculation with representativeness, The recommended acceptance criteria could be adjusted to 150mm. This study makes up for the lack of Malaysia pile foundation technical specification especially for large diameter driven piles and it will effectively promote the practical application of ones in Southeast Asia infrastructure works.

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Qualification of UOE SAWL Linepipes With Enhanced Collapse Resistance for Ultra Deepwater Applications

Volume 4B: Pipeline and Riser Technology ◽

10.1115/omae2013-10957 ◽

2013 ◽

Author(s):

Fábio Arroyo ◽

Rafael F. Solano ◽

Luciano Mantovano ◽

Fábio B. de Azevedo ◽

Hélio Alves ◽

...

Keyword(s):

New Technology ◽

Large Diameter ◽

Final Analysis ◽

Load Testing ◽

Offshore Pipelines ◽

Cold Forming ◽

Collapse Resistance ◽

Offshore Pipeline ◽

Key Factor ◽

Combine Load

Large diameter UOE pipes are being increasingly used for the construction of offshore pipelines. Since oil discoveries are moving towards ultra-deepwater areas, such as Pre-Salt in Brazil, collapse resistance is a key factor in the design of the pipelines. It is known that the cold forming, and the final expansion in the UOE linepipe manufacturing process, reduces the elastic limit of the steel in subsequent compression. Due to this, the DNV collapse formula includes a fabrication factor that derates by a 15% the yield strength of UOE Pipes. However, DNV also recognizes the effect of thermal treatments and the code allows for improvement of the fabrication factor when heat treatment or external cold sizing (compression) is applied, if documented. This paper presents the qualification of UOE pipes with enhanced collapse capacity focusing the use of a fabrication factor (αfab) equal to 1. TenarisConfab has performed a technology qualification process according to DNV-RP-A203 standard “Qualification Procedures for New Technology”. The main aspects of the qualification process are presented in this paper which included significant material and full scale testing, including combine load testing, and final analysis. The qualification process achieved successful results and this will allow use of a fabrication factor equal to 1 directly in deepwater and ultra-deepwater offshore pipeline projects with a possible reduction in material and offshore installation costs and also potentially enhancing the feasibility of many challenging offshore projects.

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Seismic Retrofit Design of a 110-Year-Old Railway Bridge Founded on Liquefiable Soils Using Large Diameter Driven Piles

Geo-Congress 2019 ◽

10.1061/9780784482100.011 ◽

2019 ◽

Author(s):

Ali Ghandeharioon ◽

James Williams ◽

Bruce Hamersley

Keyword(s):

Large Diameter ◽

Seismic Retrofit ◽

Railway Bridge ◽

Driven Piles ◽

Retrofit Design

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Axial performance of micropile groups in cohesionless soil from full-scale tests

Canadian Geotechnical Journal ◽

10.1139/cgj-2018-0695 ◽

2020 ◽

Vol 57 (7) ◽

pp. 1006-1024

Author(s):

Maged A. Abdlrahem ◽

M. Hesham El Naggar

Keyword(s):

Group Performance ◽

Large Diameter ◽

Small Diameter ◽

Element Model ◽

Cohesionless Soil ◽

Drill Bit ◽

Load Testing ◽

Dense Sand ◽

Full Scale Tests ◽

Square Configuration

Hollow bar micropile (HBMP) groups are used for supporting large loads as an alternative foundation option to large diameter drilled shafts. In such cases, it may be necessary to increase the micropile’s diameter by increasing the drill bit diameter (Db). This paper investigates experimentally and numerically the effect of increasing Db and micropile spacing on the group performance. A field load testing program was conducted on four groups of HBMPs installed in sand; each group comprised four micropiles arranged in a square configuration. All micropiles were constructed with the same size hollow bar, Dh = 51 mm; two groups comprised micropiles constructed with drill bit, Db = 115 mm, and two groups comprised micropiles constructed with drill bit, Db = 152 mm. One group of each set was installed with spacing to micropile diameter ratio, S/Db = 3 and the other group with S/Db = 5. In addition, full 3D finite element model (FEM) was developed and calibrated to simulate the behaviour of micropile groups and to evaluate the failure load for groups that were not loaded to failure. The results demonstrated that micropile groups constructed with the large diameter drill bits displayed higher stiffness and load carrying capacity than the groups constructed with small diameter bits, which confirms the effectiveness of using a larger drill bit. In addition, the group efficiency ratio values at both working load and ultimate capacity were found to be close to unity for all groups. The ultimate skin friction values of grouted micropiles obtained from this study were higher than the values suggested by the US Federal Highway Administration for medium to very dense sand. It was also found that the settlement of the 4-HBMP group increased by 25% to 33% over that of a single HBMP due to group effect.

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