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.

May 13, 20212 min read

Major Advantages of Vinyl Sheet Piles over Steel Sheet Piles

Updated: Aug 28, 2021

Vinyl sheet piles (also called PVC sheet piles, Plastic sheet piles, and Synthetic sheet piles) are becoming popular and a leading choice when comes to seawall, bulkhead, and cut-off wall construction. This materials superiority may not be on over-all basis but showcases significant advantages over other sheet pile materials as follows:

Easy Handling and Installation

Vinyl sheet piles can be up to >70% lighter than other sheet pile materials, especially steel, making it easier to handle, transport, and install. Vinyl sheet piles do not swell like wood and are manufactured with strict dimensional tolerances. Due to their uniformity and consistency, installation can be done (under normal conditions) simply by impact driving and especially with the aid of excavator or a compact vibro hammer.

Cost Efficiency

Basing on market prices, vinyl sheet piles can be up to >40% cheaper than steel sheet piles and FRP sheet piles. That is material comparison alone. However, the real economical measure of it is not just the comparison of costs for the initial installation but the overall cost in the long term or throughout its life span. Since vinyl sheet piles last much longer than more traditional materials, the cost of repair is greatly reduced and replacement is delayed. Steel sheet piles incur maintenance costs from corrosion protection measures while vinyl sheet piles are maintenance free.

Corrosion Resistance

In marine applications, steel sheet piles are exposed continuously to natural influences, most especially saline water and oxygen, making them highly vulnerable to corrosion.Corrosion rates on unprotected steel averages from 0.1 m to 0.3 mm per year depending on exposure zones. The need for corrosion protection measures such as coating and sacrificial anode is a must. Vinyl sheet piles in contrary are UV and corrosion resistant.

Longer Service Life and Sustainability

Mainly due to its superior corrosion and chemical resistance, Vinyl Sheet Piles can be designed and installed with the confidence on its performance for 50 years and beyond. Vinyl has a long shelf life which means natural elements like the sun, wind, and water are not likely to break it down as quickly as other materials. With the relentless radiant energy from the sun, combined with the surrounding’s harsh elements, walls made from materials other than vinyl will eventually rot, corrode, or become a habitat or for marine-boring critters like small mollusks and crustaceans. They are also fire resistant and proven to possess adequate resistance against creep under sustained load. Vinyl sheet piles are also seen to use recycled materials in its manufacture.

Consistency of Appearance

Wood fades, paint chips, and steel rusts over time. With Vinyl sheet piles, this problem is virtually eliminated maintaining its lasting & aesthetic look for long period of time.

Equipped with vast knowledge and 30 years-experience in Sheet Piling, ESC Group has been delivering sheet piling solutions to marine structures such as bulkheads & seawalls, tide walls, breakwaters, wave breaks, jetty, groins, erosion protection, and retaining walls.

We from ESC are pleased to help you in all of your project needs. Browse through ESC's new range of sheet piles, manufactured in facilities in Europe and Asia, at www.escpvcsheetpiling.com or contact a representative near you.