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.

Aug 21, 20202 min read

Corrosion Control on Underwater Piles

Updated: Aug 28, 2021

Foundation piles are structural elements driven to deep and stable soil strata to hold main structures, such as a bridge or a building, in place. They serve as legs where foundations are rested and take form as sub-structures. Foundation piles, therefore, are the most important parts of a building or structure, aren’t they? They are designed to be really tough. But unfortunately, they are also very vulnerable and can crumple because of being exposed to harsh environment? Steel Pipe Piles are the best examples.

Corrosion cannot be totally eliminated but can be mitigated and controlled to allow structures serve their designed life spans. Corrosion protection and control include the use of inhibitors, surface treatments, coatings and sealants, and cathodic protection. These solutions can be regrouped into a well-designed program that includes the utilization of a high-performance coating system supplemented by an equally well designed cathodic protection system as follows:

Coal Tar Epoxy Coating

The most commonly utilized corrosion protection to steel sheet piles and pipe piles, due to their low-cost, high resistance to sea water, oil, and chemicals.

ESC can provide competitive solutions to all types and magnitude of project requirements.

ESC uses internationally recognized coal tar epoxy paint brands and specifications that comply with project specifications around the world. Sand blasting to SSPC10 or NACE No. 2 standards are the norm for ESC products. ESC's SSPC certified paint inspectors ensure quality of the end product's coating through all stages of preparation, application and testing. The standard color of these coatings is black.

Glass Flake Epoxy Coating

Are ideal for applications where there is expected to be impact and high abrasion environments. ESC applies strict quality controls and careful packing to ensure the coating is in pristine condition when the product arrives on your site.

Hot Dip Galvanization

The process of Hot Dip Galvanization involves coating the steel sheet or pipe pile with a layer of zinc. This is achieved by immersing the steel sheet piles in a hot bath of molten zinc. It is considered as an alternative to paint systems and produces an aesthetic shiny surface. ESC has experience and the contacts to apply such systems to steel products.

Hot dip galvanized pipe piles — Hot dip galvanized steel pipe piles

Duplex Coating System

Duplex coatings consist of a combination of hot dip galvanization and traditional epoxy coating systems.

While it is not a standard application, it might be required on special projects and ESC can offer such solutions.

Cathodic Protection

Is an effective method of corrosion protection. It increases the design life and can be replaced much more easily than reapplication of corrosion protection coatings. It is typically utilised in conjunction with corrosion coatings to form a complete corrosion protection system.

It is a sacrificial form of protection where an anode, typically made of aluminium or zinc alloy is bolted or welded to the steel structure. The steel and anode material form a galvanic cell where the anode oxidizes preferentially to the steel, hence reducing or eliminating the rusting of the steel.