Round steel tie rods and connections for sheet pile anchorage in marine structures

Sheet pile walls can be strengthened using horizontal tie rods or round steel tie bars to connect to deadman anchorages allowing taller quay walls for port facilities or abutments. Correct design of anchorage or tie back elements is vital for the stability of the structure as the main cause of failure for tied retaining walls is attributed to the tie rods, walings or anchorage (source BS6349 and US Corps of Engineers). Horizontal tie rods are typically fabricated from round steel bars ensuring loads are safely transmitted from the retaining wall to the anchorage point.

ASDO supply a number of solutions to meet the various anchorage situations encountered in practice. Traditional fixed ‘plate & nut’ connections can be used which initially are very economic but often do not allow for future movement in the structure such as settlement so can fail prematurely. Best practice in sheet pile anchorage design will use articulated tie rods which allow movement of the tie rod from its initial installation line to counter the effects of settlement in the structure. Further safety margins can be built in by using upset forged threads which reduces the stress at stiff sheet pile to tie rod connections.

ASDO offer a range of very long, high-quality, tie rods made of round steel with a variety of connections including; upset threads, forged eyes, forged T-heads and forged spherical end.

The Construction Products Regulation of 2011 (CPR) came into force July 2013 making it mandatory for structural steel elements supplied within the European Union to be supplied CE marked indicating they meet the requirements of European harmonised design codes and are ‘fit for purpose’. ASDO marine tie rods, connections & walings meet this requirement and are manufactured under ISO 9001 and EN1090 independently audited quality systems. This has allowed Anker Schroeder to successfully supply many projects around the world.

Please do not hesitate to contact us if you have any questions about other port construction accessories. We can provide you with professional advice and support for all aspects of tied quay walls from waling beams, waling bolts, plate nosing and profiled capping plates, to the optimal mooring equipment such as bollards, bespoke bollards, edge bollards, double bollards and mooring hooks. If you have any questions concerning tied sheet pile construction, port construction, marine construction etc please do not hesitate to contact us.

 

In which area are round steel anchors/ tie-rods / sheet pile anchors used?

Sheet piles are often used in special civil engineering, marine and port construction for temporary as well as permanent purposes. Sheet piling solutions often lend themselves to quay walls, bridge, ship lift and building foundations and excavation pits. In the field of hydraulic engineering, sheet piles separate land and water (sea, harbour, lock or canal). Problem situations can arise if the sheet pile embedment is too small or a change in terrain can cause the high lying soil to push the wall towards the water. To avoid failure of a sheet pile wall a secure anchorage should be provided. The main wall facing the water shall be attached by means of long tie rods to an anchor wall or deadman fixed inland. A cofferdam can be anchored by connecting tie rods from one side to the other.
The sheet piles are preferably anchored using round steel tie rods. The connection of the tie rod from  the front main wall to the rear to the anchor wall can be made individually. It is possible to connect the round steel anchors in each single sheet pile as well as to fasten them indirectly via a stiffening waling beam. In most cases, the waler consists of two U-profiles which are welded together with spacers. This is either attached to the sheet pile wall as tension waling with waling bolts or as compression waling on waling supports.
The waling performs several functions. On the one hand, it serves to align the sheet pile wall, on the other hand, it serves to transfer the loads and to fix the anchoring. The tie rods are attached to the waling via plates and nuts. To provide additional safety, the threads of the anchors should be upset providing more stress area at the threads than at the shaft of the tie rod. Thus upset threads absorb higher forces than the shaft of the tie rod system. To accommodate settlement of the ground tie rod connections should also be made in such a way that the threads are not subjected to bending. This is achieved by the use of articulated connections, eg pinned joints or spherical nuts and seating plates. By allowing the tie rod to rotate  overloading due to bending can be prevented.
Tie rods are safety critical items to the performance of an anchored sheet pile structure. By correct design of tie rods the future performance and service of the structure can be ensured for its design lifetime.

Marine Project References

Dublin Port

ASDO have supplied 160 tonnes of upset forged tie rods, M140/115 and M120/115. ASDO460 which were up to 29m long with full articulation at connections to piles and…

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