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.

Safety Aspects of Structural Steel

Oct 12, 2020
3 min read

Updated: Jun 21

Structural steel has long been one of the most utilized materials in different magnitudes of many fabrication and construction works. Steel structures can be an integral part or almost the entirety of Steel Bridges, Pre-engineered/ Prefab Steel Buildings, Offshore Structures, Heavy Steel Fabrication Units, Pressure Vessels, Material Handling Structures, and more.

While studies and discussions have shed light on aspects of cost, strength and durability, and speed of installation, many are still skeptical about the advantage of structural steel in terms of safety.

There are features of steel itself and behaviors as a structure which has a positive influence on safety.

ESC fabricates access chambers for tunneling projects.

Here is to explain some of the most notable among them.

Structural steel and reinforced concrete both produce structures that are strong enough to withstand fire, strong winds, heavy snow, termites, and fires. However, steel structures have the most significant advantage over concrete structures when it comes to resisting earthquakes.

ESC fabricates a pre-engineered building structure for the expansion upgrade of a brewery in Papua New Guinea

Lightness and ductility of steel help the structural frame to absorb and reduce the earthquake’s destructive impact. High-strength steel connections allow slight deformation at the joints but manage to hold members from separating, preventing easy collapse of the building or sections under stress. According to an article from The New York Times, steel has better performance than concrete in seismic zones. This is ultimately the reason why earthquake-prone Japan generally avoids the use of concrete for above-grade structures. It is because concrete is rigid, heavy, and lacking resilience.

Besides earthquakes, steel-framed structures perform better against natural phenomena such as hurricanes and snow loads, and man-made circumstances like explosions. The extraordinary tensile strength of steel is the reason behind it.

Steel is non-combustible and does not ignite or spread flames. This property helps a steel structure to prevent the rapid spread of fire and sudden collapse. Although steel loses strength when exposed continuously to extremely high temperatures, it gives warning as it buckles or deflects before finally crashing. That moment, which can be as fast as a blink of an eye or a couple of seconds, means everything in a matter of life and death.

Steel structures are conductible or well-grounded and are less likely to be hit or damaged by lightning. A steel-framed building permits lightning current to pass harmlessly through the steel members and then into the ground. Materials with greater resistance to electricity are more likely to absorb structural damage when struck by lightning. A steel building with a properly installed lightning protection system is safe against that fearsome 1,000,000 volts of electricity.

Labor work using steel solutions can be reduced by up to 50% compared to other alternatives. The fewer workers employed at a given project, the fewer lives are exposed to danger. Risks and hazards associated with heavy congestion and traffic at work areas are also eliminated.

Pre-fabricated steel building solutions appear to make construction time significantly shorter. The shorter duration to complete a project also means less time of exposure to hazards. Pre-fabrication of multiple structural steel elements in controlled environments not only promotes quality but minimizes work at heights. Because steel components are delivered to the site as assemblies, a minimal number of workers and a short timeframe are required to finish the installation.

Recycling is a process that enhances environmental safety. Steel is the most recycled material at present, with at least 80% of it generated from recycled products. Steel can be recycled repeatedly or reused without further processing. Steel is a greenhouse material contributing to not just the safety of a team of workers or a group of building occupants, but also the planet Earth.

Quality assurance check on steel structures is an easier task to perform because all members are exposed and accessible. This is essential when the integrity of structures, after the occurrence of any kind of phenomenon, must be assessed to determine whether they are capable of safely continuing their service.

ESC Steel Structures was contracted by Waagner Biro Gulf Middle East Bridge Division for the specialty heavy steel fabrication of the heavy pipe arch for a new foot bridge over Al Ittihad Road, one of the busiest roads in Dubai.

Some experts claim that the overall performance of any building against seismic activity is more a function of design rather than the material used in construction. However, structural steel is obviously becoming a top choice of designers and owners because of its promising properties and characteristics.

Do not take chances, seek professional assistance! Please contact us at info@escsteel.com, visit our website www.escescsteelstructures.com.