The Soil Mixing Solution
Due to the engineering difficulties of the site, deep soil mixing was specified to stabilise the embankment and ground behind the existing sheet pile walls to a maximum depth of 11m.
Together with repairs to in situ piles, soil mixing dramatically improved the soil properties so that stresses on the sheet piles and anchors were reduced to extend the design life of the structure at Tetney Lock.
At the start of the project additional ground investigation works were undertaken and soil mixing trials were conducted.
Each soil sample was mixed in the Deep Soil Mixing Ltd laboratory and then tested to identify the most appropriate binder or combination of binders.
The weak soils of the embankment were then improved using Deep Soil Mixing’s bespoke double rotary mixing head that soil mixed the whole embankment and provided a solid bund that reduced the pressure on the sheet piles, supporting the entire structure and extending the design life.
The work was carried out from a base machine situated on the main access road across the tidal pointing doors and installation was carried out using a double rotary mixing head. Central embankment
columns were installed in front of the rig, in order to improve loading capabilities for the advancing rig to then install columns either side of the embankment.
Throughout the project, the work needed to comply with the Wildlife and Countryside Act 1981 – soil mixing complemented this need, given it has no adverse impact on the environment thanks to the soil being mixed in-situ with little noise and no vibration.