Mudmat Bearing Capacity

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OTCD-ROM DOCUMENT REPORT OTC 3750 TEMPORARY SEAFLOOR SUPPORT OF JACKET STRUCTURES Steven C. Helfrich, Alan G. Young, and Clarence J. Ehlers, McClelland Engineers, Inc. Copyright 1980 Offshore Technology Conference This paper was presented at the 12th Annual OTC in Houston, Tex., May 5-8, 1980. The material is subject to correction by the author. Permission to copy is restricted to an abstract of not more than 300 words. ABSTRACT Prior to foundation pile installation, offshore jacket structures require temporary seafloor support provided by the jacket leg extensions, lowest level of horizontal bracing, and mud mats. Since the leg extensions are the first foundation element to contact the seafloor, the designer must first select their length to assure full penetration. A second design consideration requires an analysis to determine the amount of support provided by the jacket leg extensions and lowest horizontal bracing. If additional support is needed, mud mats must be provided and designed based on the bearing capacity of the seafloor soils. This paper recommends rational design procedures for the various foundation elements in contact with the seafloor. Additional sections describe design loadings and suggested factors of safety. Finally, five case histories are given illustrating the validity of the recommended procedures and highlighting potential problems caused by inadequate designs. INTRODUCTION Offshore jacket structures must be temporarily supported by the near-seafloor soils before driving of the foundation piles. The foundation elements that bear on the seafloor soils include the jacket leg extensions, lowest level of horizontal bracing, and mud mats if needed (see Fig. 1). All these foundation elements must be designed to support the weight of the jacket plus any additional loads imposed by environmental or construction conditions. The purpose of this paper is to recommend analytical procedures to compute: (1) the soil resistance developed on the jacket leg extensions, and (2) the ultimate bearing capacity provided by the soils supporting the mud mats and lowest level of horizontal bracing. Several case histories illustrate the validity of the proposed analytical methods and highlight potential problems that may occur during installation when foundations are not designed adequately. To achieve a safe yet economical design, the structural and geotechnical engineers must coordinate their activities in sizing

Transcript of Mudmat Bearing Capacity

Page 1: Mudmat Bearing Capacity

OTCD-ROM DOCUMENT REPORT

OTC 3750

TEMPORARY SEAFLOOR SUPPORT OF JACKET STRUCTURES

Steven C. Helfrich, Alan G. Young, and Clarence J. Ehlers, McClelland Engineers, Inc.

Copyright 1980 Offshore Technology Conference

This paper was presented at the 12th Annual OTC in Houston, Tex., May 5-8, 1980. The material is subject to correction by the author. Permission to copy is restricted to an abstract of not more than 300 words.

ABSTRACT

Prior to foundation pile installation, offshore jacket structures require temporary seafloor support provided by the jacket leg extensions, lowest level of horizontal bracing, and mud mats. Since the leg extensions are the first foundation element to contact the seafloor, the designer must first select their length to assure full penetration. A second design consideration requires an analysis to determine the amount of support provided by the jacket leg extensions and lowest horizontal bracing. If additional support is needed, mud mats must be provided and designed based on the bearing capacity of the seafloor soils.

This paper recommends rational design procedures for the various foundation elements in contact with the seafloor. Additional sections describe design loadings and suggested factors of safety. Finally, five case histories are given illustrating the validity of the recommended procedures and highlighting potential problems caused by inadequate designs.

INTRODUCTION

Offshore jacket structures must be temporarily supported by the near-seafloor soils before driving of the foundation piles. The foundation elements that bear on the seafloor soils include the jacket leg extensions, lowest level of horizontal bracing, and mud mats if needed (see Fig. 1). All these foundation elements must be designed to support the weight of the jacket plus any additional loads imposed by environmental or construction conditions. The purpose of this paper is to recommend analytical procedures to compute: (1) the soil resistance developed on the jacket leg extensions, and (2) the ultimate bearing capacity provided by the soils supporting the mud mats and lowest level of horizontal bracing. Several case histories illustrate the validity of the proposed analytical methods and highlight potential problems that may occur during installation when foundations are not designed adequately.

To achieve a safe yet economical design, the structural and geotechnical engineers must coordinate their activities in sizing

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Foundations: Bearing Capacity

Foundations: Bearing Capacity

Dynamic Bearing Capacity

Dynamic Bearing Capacity

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Soil Bearing Capacity

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Bearing Capacity of Soil

16834 Bearing Capacity

16834 Bearing Capacity

04 Bearing Capacity

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Bearing capacity failure envelopes of foundations with ... · Bearing capacity failure envelopes of ... Bearing capacity failure envelopes of foundations with ... vital reference

Bearing capacity failure envelopes of foundations with ... · Bearing capacity failure envelopes of ... Bearing capacity failure envelopes of foundations with ... vital reference

BEARING CAPACITY IS IMPORTANT

BEARING CAPACITY IS IMPORTANT

Bearing Capacity of Shallow Foundations - Kamran Khankamrankhan.yolasite.com/resources/Bearing Capacity of Shallow... · INTRODUCTION Bearing capacity is the power of foundation soil

Bearing Capacity of Shallow Foundations - Kamran Khankamrankhan.yolasite.com/resources/Bearing Capacity of Shallow... · INTRODUCTION Bearing capacity is the power of foundation soil

Bearing Capacity Analysis Over Mudmat Foundations Under ...

Bearing Capacity Analysis Over Mudmat Foundations Under ...

ULTIMATE BEARING CAPACITY OF CEMENT COLUMNS TREATED PEAT …umpir.ump.edu.my/15869/1/Ultimate bearing capacity... · ULTIMATE BEARING CAPACITY OF CEMENT COLUMNS TREATED PEAT SOIL

ULTIMATE BEARING CAPACITY OF CEMENT COLUMNS TREATED PEAT …umpir.ump.edu.my/15869/1/Ultimate bearing capacity... · ULTIMATE BEARING CAPACITY OF CEMENT COLUMNS TREATED PEAT SOIL

Computational of soil bearing capacity under shallow ... · 5. Target bearing capacity and allowable settlement Assuming that the target allowable bearing capacity after soil improvement

Computational of soil bearing capacity under shallow ... · 5. Target bearing capacity and allowable settlement Assuming that the target allowable bearing capacity after soil improvement

11 Bearing Capacity

11 Bearing Capacity

Bearing capacity shear_wave

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ch3 Bearing capacity of shallow foundations 56-108ced.ceng.tu.edu.iq/images/lectures/dr.farouq/ch3-Bearing-capacity... · where a close approximation of ... Table (3.3): Bearing capacity

ch3 Bearing capacity of shallow foundations 56-108ced.ceng.tu.edu.iq/images/lectures/dr.farouq/ch3-Bearing-capacity... · where a close approximation of ... Table (3.3): Bearing capacity

General Bearing Capacity

General Bearing Capacity

Bearing Capacity v1.00 Sept2010

Bearing Capacity v1.00 Sept2010

Bearing Capacity Piles

Bearing Capacity Piles

1 Bearing Capacity Theory Bearing Capacity. 2 Bearing Capacity Failure a) General Shear Failure Most common type of shear failure; occurs in strong soils.

1 Bearing Capacity Theory Bearing Capacity. 2 Bearing Capacity Failure a) General Shear Failure Most common type of shear failure; occurs in strong soils.

The Bearing Capacity of · PDF file•-Brinch Hansen’ Method ... The General Bearing Capacity Equation. The Terzaghiultimate bearing capacity equations presented previously are for

The Bearing Capacity of · PDF file•-Brinch Hansen’ Method ... The General Bearing Capacity Equation. The Terzaghiultimate bearing capacity equations presented previously are for