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.

Economic Contribution of Cathodic Protection Against Corrosion

Estimates of the cost of corrosion ranges from 1 to 5% of the Gross National Product (GNP) of a country. Yes, that is billions to trillions of moneys lost unnoticed. Whether mild or severe, corrosion on metals especially steel can cause expensive or irreparable damage to equipment and vital structures.

Corrosion is almost unstoppable and expensive to repair when it has started. This is why it must be anticipated or treated as early as possible to avoid major losses.

The most economical way to prevent corrosive disasters is to employ corrosion protection on steel right in the first place. However, deciding on what preventive measure to adapt is crucial.

What is Corrosion?

Corrosion is the deterioration of a material, often a metal, due to reaction to its environment – atmospheric conditions.

The word corrosion comes from the Latin "corrodere" meaning "to gnaw to pieces."

The Effects of Corrosion

Corrosion causes harsh damage to steel, weakening and losing its efficiency, which causes failure, and affects infrastructures, businesses, people, and even the environment.

Primarily, it impedes the efficacy of products used in the construction, such as the corrosion of materials used significantly in construction projects exposed in water, buried, or submerged systems, including sheet piles, steel pipes, marine bollards, and fabricated steel structures, and other steel products.

Furthermore, corrosion in construction industries often leads to revenue loss and increased operations or maintenance costs.

Types of Corrosion

There are many types of corrosion, but the most common are electrochemical and environmental. Electrochemical corrosion process occurs when metals are exposed to oxygen and water. This combination creates an electrolyte that can cause the metal to corrode.

Environmental corrosion is a natural process that occurs when metal mingles with water and oxygen. This combination causes a chemical reaction that breaks down the metal. The rate of corrosion depends on the type of metal, the amount of water and oxygen exposure, and the presence of other chemicals.

Corrosion Protection on Steel: How to Control Corrosion

Corrosion, even it is a normal occurrence, is still a controllable process.

There are many ways to control corrosion including protective coatings, corrosion-resistant alloys, the use of sacrificial anodes or cathodic protection, and more.

The most common and simplest way to control corrosion is protective coating. This works by applying coating films on metals to create a barrier between the material substrate and underlying substance or environment. Paint is a very common type of protective coating but tar, bitumen, and plastics such as polyurethane are also used. Powder coating has also become popular due to their effectivity in many applications.

Another method of corrosion protection is cathodic protection. This method controls corrosion on certain metals by using a more corrosive coating on their surface such as zinc. Galvanizing or hot dip galvanization and anodizing are those of the exact illustrations of this technique. As a weaker element, the coating corrodes in place of the encapsulated metal or steel.

Corrosion Protection Using Steel Sacrificial Anodes

The use of steel sacrificial anodes is one type of cathodic protection especially for submerged or underwater steel or metals. Sacrificial anodes are more corrosive types of metals such as zinc, aluminum, and magnesium. They are attached to the more superior, protected steel knowns as cathodes, to sacrifice themselves to corrode instead of the cathode. These sacrificial anodes are placed strategically in locations where they will effectively protect the steel from corrosion.

Economic Impact of Corrosion

In 2016, NACE has estimated a loss amounting to $2.5 trillion which is equivalent to 3.4% of the global GDP. Developed countries generates most of these costs. In United States alone, corrosion costs around over $300 billion a year.

Production and usage of corrosion-resistant materials have by far reduced metal corrosion losses by about 1/3. However, most of these innovative materials are not highly sustainable like steel, resulting to production limitations and high costs which are of course a problem to economies.

At the other hand, the application of cathodic protection along with appropriate coating materials has been proven to be most economical when protecting large and critical assets especially buried or underwater pipelines that carries water, petroleum products, natural gas, and others.

Corrosion has been every organization’s challenge for years when comes to keeping infrastructures functional and efficient throughout their designed life span. This is not just to protect bigger revenues and avoid enormous property damages but environmental degradation as well.

Protective Coating Services: The Economic Decision

Choosing the best corrosion protection measures for a project is an investment that can save tons of money over time. The bigger the asset, the more reasons why a high level of expertise in the business is required. Contact us today to start making a difference.

Why ESC? ESC is a proud provider of corrosion protection products and services to hundreds of industries worldwide. We have over 30 years of experience in the global market in supplying corrosion protection solutions such as Coal Tar Epoxy Coating; Glass Flake Epoxy Coating; Hot Dip Galvanization; Duplex Coating System, Cathodic Protection Systems, and Sacrificial Anodes.