Pressuremeter and Deep Foundation Design

2008 ◽  
pp. 376-376-30
Author(s):  
J-L Briaud
Keyword(s):  
Foundation Design ◽  
Deep Foundation

Analytical Method to Estimate Railroad Spike Fastener Stress

2020 ◽  
Vol 2674 (11) ◽  
pp. 379-389 ◽  
Author(s):  
Marcus S. Dersch ◽  
Matheus Trizotto Silva ◽  
J. Riley Edwards ◽  
Arthur de O Lima ◽  
Tom Roadcap
Keyword(s):  
Analytical Method ◽  
Model Development ◽  
Element Model ◽  
Foundation Design ◽  
Deep Foundation ◽  
Cross Sectional ◽  
Field Instrumentation ◽  
Key Variables ◽  
Railroad Safety ◽  
Laterally Loaded

Previous research indicates that spike fastener fatigue failures have led to at least ten derailments since 2000. Given that railroads continue to install fastening systems that have experienced spike failures, methods to quantify the stress state of the spike must be developed. Common approaches to quantify the effect of key variables include laboratory experimentation, field instrumentation, or finite element model development. However, these approaches may be both time and cost prohibitive. An analytical method based on beam on elastic foundation mechanics, similar to the analysis of laterally loaded piles in deep foundation design, was developed to estimate the spike stresses. The outcome is a laboratory-validated analytical approach that generates estimates of spike stress. This analytical model was used to investigate key design criteria (timber modulus, spike cross-sectional area, and load applied) that could be changed to improve the resiliency of the fastening system to increase railroad safety. Another outcome of this study is the development of an instrumented spike that quantifies the spike demands when installed and loaded within a crosstie.

Understanding Hybrid Subsea Foundation Design

2015 ◽  
Author(s):  
M. Kabir Hossain ◽  
Han Shi ◽  
Basel Abdalla ◽  
Markella K. Spari
Keyword(s):  
Best Practice ◽  
Real Option ◽  
Integrated System ◽  
Foundation Design ◽  
Deep Foundation ◽  
Modeling And Analysis ◽  
Fea Model ◽  
Design Variables ◽  
Hard Limit ◽  
Soil Sensitivity

Hybrid subsea foundations (HSF) are combined foundation systems of mudmats and piles. The primary motivation of combining these two foundation types is to provide greater resistance to large horizontal loads in addition to vertical loads, for which use of mudmats alone will require it to be of impractically large size. The contribution from the piles in the lateral capacity helps to limit the size of the mudmat, which is critical in subsea environment. In a brownfield situation, this is sometimes a hard limit with only limited space available to place a new mudmat in the existing field layout. Also, in some cases, the HSF may prove to be a more economical option for resisting large horizontal loads compared to, for example, to suction piles. While the authors are aware of some scattered project-specific design and use of subsea mudmat-pile hybrid foundations by individual contractors and operators, there is no industry-wide publicly known best practice currently available. These designs of HSF appear to be generally based on simplified analytical approach that require superimposition of conventional shallow and deep foundation capacity calculation methods, hence violates the static and kinematic compatibility requirements fundamental for a sound and robust prediction procedure. This paper attempts to provide some insight into the behavior of mudmat-pile foundations as a hybrid integrated system numerically using finite element modeling and analysis (FEA). The interactions between the mudmat and the piles in an HSF are complex and hence a FEA-based approach is considered most suitable. The FEA model in this study included the mudmat, the corner piles, the pile-mudmat connections and the seabed soil. Sensitivity of the HSF capacity to the size of the piles (length and diameter), the connection type of the piles to the mudmat, and the number of piles are selectively investigated and the results presented. Based on these results some pertinent observations relevant to design of HSFs are also given. While the study is of limited scope, it offers important insights into the effects of the primary design variables on HSF’s capacities. Therefore, the authors hope the information herein will be of benefit to practicing subsea engineers who might have to face choices to consider mudmat-pile hybrid foundations as a real option for their projects.

Volume 14 Issue 1 Editorial Note

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Anne Lemnitzer
Keyword(s):  
Ground Improvement ◽  
Soft Clay ◽  
Lateral Spreading ◽  
Editorial Note ◽  
Foundation Engineering ◽  
Load Testing ◽  
Highly Qualified ◽  
Foundation Design ◽  
Deep Foundation

The first of two issues in 2020 is a mix of research and case study papers. 2020 is an exciting year for the DFI Journal as we expanded our editorial board with a set of highly qualified editors with various expertise in deep foundation engineering, ground improvement, slope stabilization, QA/QC of pile elements, load testing, seismic foundation design, and innovative foundation construction technologies. The first paper is a 2019 Student Paper Competition Award winner; the second covers factors of safety for drilled shaft foundations; the third presents results of models of pile-supported wharves subjected to inertial and liquefaction-induced lateral spreading loads; the fourth presents analysis of static loading tests on CFA piles in clay and sand; and the closing paper is an analysis of soft clay parameters on an existing quay wall in Egypt.

Deep foundation design in the new Ontario Highway Bridge Design Code

1983 ◽  
Vol 20 (1) ◽  
pp. 173-176
Author(s):  
Bengt H. Fellenius ◽  
Geoffry G. Meyerhof
Keyword(s):  
Dynamic Monitoring ◽  
Pile Groups ◽  
Design Code ◽  
Bridge Design ◽  
Limit States ◽  
Foundation Design ◽  
Deep Foundation ◽  
Capacity Limit ◽  
Load Tests ◽  
High Level

A review is presented of some aspects of deep foundation design in the new Ministry of Transportation and Communications of Ontario, ultimate limit states Bridge Design Code. The design of axial pile capacity distinguishes between structural capacity limit and geotechnical capacity limit. The geotechnical capacity of a driven pile is governed by the dynamic impedance of the pile cross section. Higher geotechnical capacity, for instance due to soil setup, can only be utilized if proven to exist. Different capacity modification factors are used for routine load tests and high level test loading. Modern methods of dynamic monitoring are included and capacity determination by such methods is accepted as equivalent to determination from routine load tests. Lateral capacity of single piles and group piles, downdrag, and inclined loading of pile groups are considered, as are details such as splicing and use of pile shoes. Pile spacing is given as a function of expected pile length.

Deep foundation design in the new Ontario Highway Bridge Design Code: Discussion

1983 ◽  
Vol 20 (4) ◽  
pp. 858-859
Author(s):  
Baidar Bakht ◽  
Leslie G. Jaeger ◽  
Roger A. Dorton
Keyword(s):  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Foundation Design ◽  
Deep Foundation

scholarly journals Investigation of Uplift Capacity of Deep Foundation in Various Geometry Conditions

2019 ◽  
Vol 13 (1) ◽  
pp. 344-352
Author(s):  
Danial Jahed Armaghani ◽  
Houman Sohaei ◽  
Eshagh Namazi ◽  
Aminaton Marto
Keyword(s):  
Critical Factor ◽  
Influential Factors ◽  
Future Research ◽  
Small Scale ◽  
Embedment Depth ◽  
Deep Foundations ◽  
Foundation Design ◽  
Deep Foundation ◽  
Power Generators ◽  
Uplift Resistance

Background: Uplift resistance of deep foundations or piles is a critical factor for deep foundation design in several civil engineering applications such as electric transmission towers, communication towers and wind power generators. Therefore, the behavior of the pile under uplift load, together with its influential parameters, should be studied to provide a proper design. Objective: The aim of this study was to identify the effects of pile geometry, including diameter and embedment depth on the Maximum Uplift Resistance (MUR) of the small-scale piles. Methods: To achieve the aims of this study, a total of nine laboratory experiments having various pile diameters (i.e. 9 mm, 12 mm and 15 mm) and embedment depths (i.e., 10 cm, 15 cm and 20 cm) were planned, designed and conducted. Results: Generally, the results indicated that both diameter and embedment depth have a significant effect on the MUR of piles. The values of the MUR of piles were increased by increasing the pile diameters in all conducted tests. Furthermore, a significant increase in the MUR results was observed when the embedment depths are increased from 10 cm to 20 cm. Moreover, in all cases, small-scale piles were failed in embedment depths ranging from 5 mm to 10 mm. Conclusion: It was concluded that pile geometry has a deep impact on the MUR of the piles. Future research can be done to investigate the effects of other influential factors on the MUR.

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