Ground improvement suggestion on reclamation area

[vinothsekar]

Hello everyone,

we are doing the reclamation in one of our projects with an area of 400m x 50m from -2m to +1m. Also, we are treating the reclamation ground with PVD to decrease the future settlement with proloading fill and the height of the fill is 5m above +1.0m to achieve the future settlement criteria less than 10cm. Below reclamation fill, the strata is consists of SILT & CLAY from -2m to -33m with N value 1 to 5 and Cu is 5kpa to 15kpa. The entire area is proposed to do PVD to decrease the future settlement of the building and utilities.

Now, if we install a verticle wall (sheet pile) to the protect the shore then lateral diffection of the sheet pile is very high due to soft soil during the Ground improvement.

Can anyone suggest the suitable solution in the case to avoid the high deflection of sheet pile.

Thanks.

Vinothkumar S
Geotechnical Engineer

 

[EireChch]

You can tie the wall back into CLAY but may need a lot / long anchors, consider a dead man maybe.

Could also consider treating the clay within zone of influence of the wall. Stone columns might be an option. Although I have never seen anyone install anchors through stone columns so that might not be the best idea!

Could lower the lateral pressure on the wall by excavating behind it and replacing with light weight fill.

A few options there, none perfect.

 

[vinothsekar]

Eirechch,

We have received an offer from one of the vendor proposing peripheral stone column behind the sheet pile wall. Commerically the offer is too high.

Also, we have executed tie rod method to retain the sheet pile in our previous project for 30m width using deadweight wall from other end The present proposed area is 50m width and executing largr width 50m is little critical.

I hope, excavating behind the wall and replacing with light weight fill could be considerable option.

Any other suggestion shall be appreciated.


Vinothkumar S
Geotechnical Engineer