Let’s start with Larssen sheet piles. Larssen set of sheet piles are famous and well known to civil engineers worldwide. Their reliability, versatility and strength in all types of condition as retaining structures has beenwell proven and documented many times over.
Here is a little bit of history of this famous sheet pile. In 1902, Mr Tryggve Larssen, State Chief Engineer at the City of Bremen in Germany, developed the world’s first steel sheet pile, which has U section with riveted interlocks. Thus this how the name of this sheet pile comes about.
Larssen U Section Sheet Pile
The interlocking idea on both sides of the sheet pile came about In 1914. This is still utilized all over the world as the most popularsteel sheet pile section.
One of the oldest Larssen U pile is displayed at Giken Kochi Head Office to remind us of the historical background of U steel sheet pile. The picture below is a typical larssen sheet piles stacked together.
The interlocking system mentioned above can be seen from the photo on the left. On both the sides of the sheet piles have U shapes which can be used to interlock to another sheet pile.
The interlocking system creates a water tight and increase the strength the sheet pile structures. Be it cofferdams or earth retaining systems.
Here is a diagram thats show how interlocking is done
(This article comes from hsmetalproduct.com editor released)
The Dawson Universal Sheet Pile Threader has been developed to enable a safe, easy and productive method of pitching sheet piles. The need for a “top man” is eliminated as all operations can be performed at ground or top frame level. The Universal Sheet Pile Threader can be set up for virtually all Z section and Larssen sheet piles, and once set correctly will quickly interlock the piles with one simple movement. Care should be taken during the set-up procedure to ensure that each adjustment is accurately set, extra time spent here will be saved tenfold during operation. Within one pile section there may be several variations. On a “Z” section interlocks are usually different at each end. The leading can also be left or right hand. The Universal Sheet Pile Threader can accommodate these variations with the simple adjustment of roller positions. This can be accomplished on site by offering the Sheet Pile Threader up to a pile and adjusting the rollers to the correct position. They are now set for a left or right hand threading.
Sheet pile threaders offer a complete ‘feet on the ground’ approach to steel sheet piling when used in conjunction with remote release shackles. Improve productivity and working safety.
The one basic guide frame is standard for ALL “Z” section piles, ALL straight web piles and “U” piles of size 2 and upwards. Below this size may require modifications to the main frame, but the principal of operation remains the same.
The different sections are accommodated simply by inserting appropriate rollers onto the lower spindles which form part of the lower clamp. These rollers fit the pile profile to give positive and accurate location.
(This article comes from Dawson Contruction Plant editor released)
PZ and PZC sheet piles are also called Larssen sheet piles, mostly used in USA. Some middle American countries also prefer these sections.
Larssen sheet piling has been widely used in the transformation of waters and along the coastal areas of infrastructure. The development of China’s economic will occur wiht the series of mega projects, at the same time, China’s high-speed railway, intercity rail lines, construction of State Road highway traffic, all needs foundations and cofferdams. In the natural state of crushed gravel (particle size less than 20mm), sand, silt, etc., foundation bearing capacity in 100KN / m2 following geological conditions, hot rolled steel sheet piling can be driven up to 30 times
Hot rolled steel sheet piling use a thin sheet (common thickness 8mm ~ 14mm), to roll forming machine processing. Its low cost of production and the price is cheap, length control is also more flexible. But the simple processing methods and the same thickness all sheet piles, also result in increased cross-sectional dimensions and cannot optimize the amount of steel.
According to the actual situation of the project, client can select the most economical and reasonable cross-section, optimize engineering design, material savings of 10-15% compared with the performance, greatly reducing the construction cost.
The history of sheet piling goes back to the beginning of the last century. The book Ein Produkt erobert die Welt – 100 Jahre Stahlspundwand aus Dortmund (A product conquers the world – 100 years of sheet pile walls from Dortmund) describes the success story of sheet piling. The story is closely linked with Tryggve Larssen, government building surveyor in Bremen, who invented the sheet pile wall made from rolled sections with a channel-shaped cross-section.In 1902 the so-called LARSSEN sheet piles – known as such from this date onwards – were used as a waterfront structure at Hohentorshafen in Bremen – and are still doing their job to this day! Since then, have been manufactured in the rolling mill of HOESCH Spundwand und ProfilGmbH.
Over the years, ongoing developments in steel grades, section shapes and driving techniques have led to a wide range of applications for sheet piling. The applications include securing ex- cavations, waterfront structures, foundations, bridge abutments, noise abatement walls, highway structures, cuttings, land fill and contaminated ground enclosures, and flood protection schemes. The main engineering advantages of sheet pile walls over other types of wall are:
- the extremely favourable ratio of steel cross-section to moment of resistance,
- their suitability for almost all soil types,
- their suitability for use in water,
- the fast progress on site,
- the ability to carry loads immediately,
- the option of extracting and reusing the sections,
- their easy combination with other rolled sections,
- the option of staggered embedment depths,
- the low water permeability, if necessary using sealed interlocks, and
- there is no need for excavations.