What is the application of combi walls? As an efficient solution adding strength for different applications, combi walls can meet client’s diffrent project requirements. Utilizing a range of components like sheet piles and king piles, combi walls play a vital role in construction filed, including rivercofferdams, bridge pier protection, foundation and levee constructiont.This article will introduce more information about where and how to apply the combi walls systerms.
This article contains the following:
The comprision of combi walls
The scope of application of combi walls
The advantage of combi walls
Combi walls are pile walls comprised of high modulus structural components, connected by light sheet piles. The high modulus components，or also called king piles，can be tubular, box, bearing or other types of fabricated piles. Driving these piles is a tough task, Because the driving sequence of the king piles must ensure that the pile toe encounters soil uniformly on its total circumference and not just on one side. The process of riving the king piles must be carried out with extreme care to make sure that they are installed straight and vertical, guaranteeing that they are parallel to each other and at the standard spacing. Therefore, A stable, adequately heavy, rigid and straight pile-driving template frame, which suits the length and weight of the pilings is essential. After removing the guide frame, the final inspection shall be carried out to ensure the deviation of the distance between the king posts is within acceptable tolerances to allow appropriate Installmenet of sheet piles. However, if the deviation exceeds the specified or actual tolerance, the intermediate piles must be adjusted or must be pulled out and repiling. To overcome the difficulty of driving conditions, we can use some methods: jetting; excavating inside the king piles; or any other ground pre-treatment methods normally adopted for sheet piling.
When the standard systems of sheet piles does not have enough strength to resist the required design load, the combi wall system is an ideal choice. King pile bears most bending loads, and the filling sheet pile in the middle transmits soil pressure and water pressure to King H pile. Filling sheet piles can be shorter-between 60 and 100% of the length of king piles. H pile combi wall uses King H pile and filled sheet pile as intermediate elements to transfer load and provide cutoff. Compared with individual sheet piles, these can provide excellent structural performance. The scope of combi wall application incudes rivercofferdams, bridge pier protection, foundation and levee constructiont.
Combi walls have many supior properties compared with other pilling systerms. FIrstly, The main advantage of this wall is the great stiffness of the whole, which also increases its bearing strength and provides more economical support than the secant wall. The combi-wall is stabilised by installing horizontal struts or anchors in the soil behind it, so it has greater load-bearing capacity than the sheet wall. For heavy marine buildings and deep foundation applications, pile walls usually require high bearing capacity and stiffness. When the conventional sheet pile wall is insufficient, the combi wall system can be needed to achieve the required performance.
It is effective in temporary application because it can be easily removed and reused once the steel elements are no longer needed. Sheet piles are only required to resist active soil pressure as low as zero soil pressure levels, and can be extended below that level to ensure safety. By horting the length, sheet piles can reduce the cost of construction and improve the facilitaty of installation.
The introducyion of combi walls is as described above, combi walls is a popular construction method in buiding, bridge foundation and many other field thanks to its great facility of installment and wide range of application. Nowadays, more and more projects prefer this economical and efficient system.