It refers to the pile’s ability to be driven to a specified depth without receiving any harm. The ultimate resistance of soil to a pile that can be driven without causing damage with appropriate driving equipment sets a limit for pile drivability. Drivability of Pile Driving Pile Drivability Influencing Factors A pile must meet two important drivability characteristics: pile stiffness and pile strength. To be able to transfer enough driving force to overcome soil resistance, the pile must be rigid enough. In terms of pile strength, it should be sufficient to allow the pile to sustain the driving force without being damaged. The main determinant of pile drivability is pile impedance (EA/C). The modulus of elasticity.
Table of Contents
What is pile drivability
The pile’s elasticity (E) is determined by the material used in its construction, the pile wave speed (C), and the cross-sectional area of the pile (A), which appears to be the sole parameter that can increase pile drivability. When a steel pile is chosen, the improvement in pile drivability may be easily seen by increasing the cross sectional area. Increases in the thickness of steel pipe piles, for example, will improve pile drivability. However, if the area of the reinforced concrete section is raised, so does the soil resistance. Pile driven system characteristics like as speed, stroke, ram weight, and actual pile driving system performance on the job site all have an impact on pile drivability.
The applicability of Cone Penetration Test (CPT)-based axial capacity techniques, which are used to estimate pile static capacity, to the prediction of pile driveability is investigated in this work. A driveability study is undertaken to investigate the impact of various operating parameters. The ability of a number of axial capacity techniques (IC-05, UWA-05, and Fugro-05) to estimate the driveability of open-ended steel piles used to support, for example, offshore jackets or bridge piers is evaluated in both unmodified and modified form. Changes to the proposed base resistance to account for the resistance mobilised under discrete hammer blows and the presence of residual loads, as well as accounting for the effects of static capacity increases over time, are among the modifications to the CPT-based design techniques.
Factors Influencing Pile Drivability
The driveability of a pile foundation is critical for pile design. In real-world projects, precise pile driveability assessments would prevent the pile from being cut off or damaged if it couldn’t drive into the specified depth, as well as keeping pile bearing capacity at or above design capacity when penetration depth is greater than design depth. This research investigates the sensitive aspects that may effect pile foundation driveability analysis in order to accurately analyse pile foundation driveability. The pile driving analysis findings are obtained after 32 trials are designed using orthogonal experiments and completed by grlweap. The same results can be obtained on the sensitivity regularity of pile foundation driveability influencing elements using the case study of the Bohai sea oil field platform project.
Dynamic methods, such as impact or vibration, are used to penetrate the ground. The relationship between the static analysis results given on the plans and the dynamic methods of field installation is critical to obtaining a successful pile foundation that meets the design objectives. The following site-specific issues can be answered using dynamic analysis: Is it possible to use a specialised hammer to drive a pile to the predicted depth and capacity? If that’s the case, what will the last blows’ set (deflection) be, and what will the pile’s maximum stress be? What hammer qualities are required to properly complete the project with the pre-selected pile if driving cannot be done as indicated in? What other pile of the same length might possibly be driven instead?
Pile impedance
Rational analysis based on the hammer-cushion-pile-soil system (dynamic analysis) is effective for answering these and other concerns that may arise in connection with a specific piling project. Both the design and construction stages of a project should include dynamic analysis. Driveability of Pile The greatest soil resistance to which a pile can be driven without damage is the limiting pile drivability for a certain pile-soil condition. The developed soil resistance is determined by the pile dimensions and subsurface profile. A pile penetrating very soft soil to bear uniformly on sound un-weathered rock with no transition zone of weathered rock is an exception to this maximum. In this unique scenario, a pile’s full structural strength can be developed without causing considerable damage.
Prior to driving production piles, static load testing can be used to assess drivability. Normally, test piles are driven to predetermined lengths and then loaded. Load tests can be carried out at any time during the design and/or construction process.Analysis of Wave Equations This method takes pile stiffness into account when predicting driving stresses and the link between hammer blow count and ultimate pile capacity. It can be used to determine drivability before to driving, design the most cost-effective pile wall thickness or pile section, and choose driving equipment. Measurements in Motion These measurements, as well as their analysis, can be utilised to calculate pile driving stresses and static bearing capacity. It may also provide a wave equation with static soil resistance distribution and damping factors.
Methods to Assess Pile Drivability
Drivability issues arise with single-material solid-section piles such as steel H, precast concrete, and wood, especially when permitted design stresses rise. Drivability is generally limited by the pile’s compressive strength in the case of lengthy prestressed concrete piles, but tensile strength will be crucial in the early driving stage where enormous hammer energies may be unbalanced to the little soil resistance. Extreme Marine Construction used an excavator-mounted Pile Master air hammer to drive wooden piles. Equipment Corporation of America is the photographer for this image (ECA)Mechanical Reliability in any sort of machinery, mechanical losses are unavoidable. They can occur in pile driving equipment because to frictional losses between the moving (ram) and stationary (frame) elements, losses due to back-pressure in the valving of air/steam and hydraulic hammers, or losses due to back-pressure in the valving of air/steam and hydraulic hammers.
Comparing net striking energies rather than efficiency is a recommended technique to evaluate hammers based on their impact energy. Other considerations to consider are the (effective) stroke’s relationship to the ram weight, the type and amount of cushion material, and the impact of the required compression in diesel hammers. In most wave equation investigations, the rated striking energy is multiplied by an efficiency, yielding a net striking energy. When driving batter heaps, another component in the lowering of output energy occurs. This is commonly referred to as a “efficiency” factor, however it is not. It’s caused by the hammer’s geometry in relation to the gravity field, and it’s most noticeable with single-acting hammers.
Driveability and Pile Type
To determine which cushion will effectively restrict the driving forces caused in the hammer and pile while yet producing the largest potential permanent pile set per hammer blow, or to optimise the cushion. To determine the correct driving hammer size. This decreases the likelihood of picking a huge, expensive hammer whose capacity is unnecessary and whose use might result in pile damage. The more terrible case occurs when a tiny hammer is used, only to discover that its driving capacity is insufficient to drive the pile to the requisite resistance or depth. The purpose of this study is to determine the impact of the driving accessories. It has been demonstrated that the driving accessories absorb a significant amount of the overall energy output in several circumstances.
Pile driving is the process of installing a pile — a braced, structural column.
Common modes of pile damage include: yielding or crushing at the pile head, toe or shaft.
GRLWEAP is a one-dimensional Wave Equation Analysis program that simulates the pile response to pile driving equipment.
Also Check
Photocatalytic Self-Cleaning Concrete – Properties, Applications, Advantages