What is the proper vinyl sheet pile driving method for different soil types?

“Pitch and drive” method is the most practical way of pile driving in loose soils especially when using short piles. Also called “set and drive”, this method installs piles one by one. However, with only one interlock in control, sheet piles have high tendencies of rotating from the axis and leaning forward or backward. Panel driving is recommended for the dense deposit of sands and compact cohesive soils such as heavy clay or in presence of obstructions. In this method, a number of piles are interlocked together before driving. The panel of piles is supported by guide frames and driven gradually in sequence, sometimes in a staggered manner. The method can achieve installations of longer piles in more difficult ground conditions with better results in sheet pile alignment and verticality. In cases of difficult ground conditions such as hard strata and the presence of obstructions, driving assistance is employed along with a proper selection of driving method and equipment. Jetting and drilling help by loosening or eliminating obstructions by creating pressure right under the tip of the sheet pile being driven. Long and slender PVC sheet piles require steel mandrels as supports when driven in such conditions. Mandrel, which shape is similar to sheet pile profiles, increases the rigidity of Plastic Sheet Pile and supports the weight of the driving equipment such as a vibro-hammer.

What is the proper machine to drive piles in different conditions?

Impact driving is suitable for all soil types but appears to create the highest degree of stress to sheet piles. It is more appropriate to cohesive soils and soft soils such as silts and peats, loose medium to coarse sand, and gravels free of rock inclusions. Drop hammers such as the hydraulic hammer are the common types of impact-driving machinery. Driving using vibratory hammers is ideal for non-cohesive or granular soils such as soft soils and round-grained sand or gravel. It has also shown satisfactory performance in sandy, silty, or softer clay soils. It is less effective in angular-grained materials and soils with a firm consistency. With the introduction of vibration, however, the sub-soil can be further compacted, increasing penetration resistance and ultimately-refusal. If this is the case, driving aids like jetting and drilling might be necessary.

What are the pvc sheet pile selection criteria for soil condition of different hardness?

General rule of the thumb: “the harder the soil, the stronger and stiffer sheet pile section should be used”. Driveability of a pile section is a consequence of its cross-sectional properties (thickness, depth, and width), designed shape, length, grade, and the applied load. Hardness of soil strata characterized by SPT or CPT values is used to predict soil resistance which is essential in the calculation of driving force to be applied. Knowing the range of force from the selected driving machine, corresponding sheet pile sections can be picked according to their yield strength and elastic modulus.

How should I choose a sheet pile section for soils with, say, SPT Value, N=30? Can I still consider using vinyl or shift to steel?

Every sheet pile material has a design purpose, strengths, and areas of improvement. The availability of different materials denotes the need for a special material for a specific application. Plastic or synthetic sheet piles for example are known for being light and corrosion-resistant; Steel sheet piles are recognized for their extraordinary strength and versatility; and so on.

Dec 18, 20192 min read

Types of Marine Fenders

Updated: Nov 11, 2023

Marine fenders are a type of marine equipment that are used to prevent ships, boats and other naval vessels from colliding against each other or against docks, wharves and piers. They are also known as marine bumper. Rubber fenders are designed to absorb the energy that a vessel transfers to a berthing structure, hence the term energy absorption, so that the amount of energy received by the dock is much less compared to when fenders are absent.

Marine fenders, in today’s times are employed in such a way that they are kept on the hull or the head of a boat or a ship in order to prevent casualty to the hull or the head of the naval vessel if there is any collision happening between boats. This is an equipment that is of much significance due to the prevention of damage to both the vessel and the other surface. The main aim of installing the marine rubber fender is to protect both vessel and dock from major failure during the berthing period.

There are various types of marine fenders catering to different functionalities. ESC supplies the best designed, high performance materials for a low maintenance, long service life whatever your working demands and environmental conditions.

In order to achieve the intended result, there are several factors to consider in choosing the right type of marine rubber fender to use, namely the dimension of berthing vessels to consider the size of fenders ; the type of the port such as the location and position of the port; situation around the port to evaluate the marine environment such as high tide or low tides or the power of wind which influences the waves; and the existence tugboat to guide the vessel while berthing to avoid vessels from crashing into the port wall.

Marine fender comes in different shapes, some of the most popular ones include cell fenders, cone fenders, pneumatic fenders, arch fenders, foam fenders, cylindrical fenders, element fender and many more. Here are some of the fender types and its uses:

Cell fender is one of the most reliable, proven fender design and the most commonly used structure in the maritime industry such as oil and LNG platforms, offshore terminals, container berths and others.

Cone fender is the kind of fender that is suitable for handling different situations due to its highly efficient geometry. Its application can be in those sites with much difference in the tidal variations.

Pneumatic fenders are mainly used for transferring from one ship to another at the mid seas. This type of fenders requires minimal maintenance, so costs are minimised. The special feature of this fender is the lower reaction force at the time of lower deflection. This property makes these fenders very suitable for Ship-to-ship (STS) operations.

Arch fenders has a simple design that provides excellent shear performance. This type of fender is suitable for vessels with high allowable hull pressures due to its design. Its popular application includes general cargo vessels, workboat harbours, barge berths and more.

Foam Fenders absorb impacts even in an aggressive environment. Every cell is separate and so water cannot migrate into the foam. No matter how badly abused Foam Fenders will not burst or explode.

Types of Marine Fenders

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