Tenders Are Invited For Shafts – New Construction Of The Meisterschwanden Lake Waterworks; Special Civil Engineering Excavation Pit Pumping Station - Creation Of Bored Pile Wall & Sealing Base

Shafts – New Construction Of The Meisterschwanden Lake Waterworks; Special Civil Engineering Excavation Pit Pumping Station - Creation Of Bored Pile Wall & Sealing Base. The Municipality Of Meisterschwanden Intends To Guarantee Its Water Supply In The Long Term In The Future By Building A Lake Waterworks Using Water From Lake Hallwil. To Realize This Project, A Pumping Station Must Be Built On Lake Hallwil And A Treatment Plant In The Area Of ​​The Meisterschwanden Sports Field. The Pumping Station Of The Seawater Pumping Station Is Planned North Of The Hotel Seerose At A Distance Of Approx. 35 M From The Lake Shore And Consists Of A Structure Around 9 M Deep, Which Is To Be Built In A Shaft With An Inner Diameter Of Around 6 M. The Shaft Is Created Using A Secant Bored Pile Wall Made Of 34 Piles With A Diameter Of 0.9 M. Due To The Hydrogeological Conditions And For Reasons Of Space, Only A Bored Pile Wall Was Possible For The Approximately 9M Deep Excavation Pit, Whereby The Embedment Depth Of The Piles Was Chosen Above The Groundwater And Gas-Bearing Layer. The Secant Bored Pile Wall Is Combined With A Jetting Sealing Sole. The Overlapping Bored Pile Wall And The Sealing Sole Must Be Made Watertight And Gastight. After The Construction Of The Bored Pile Wall And The Sealing Base Has Been Completed, The Construction Pit (Lot 2) Will Be Drilled Horizontally In The Lower Area By A Drilling Rig From A Third-Party Company Installed Approximately 60M To The East Using A Flushing Borehole. The Pilot Hole Is Expanded And The Seawater Pipe (Hdpe 315Mm) Is Subsequently Pulled Into The Excavation Pit. Bentonite Will Be Used As A Supporting Fluid During This Work, Which Will Solidify In The Excavation Pit Area. So That The Drilled Piles Can Be Driven Through With The Flushing Bore, Grp Reinforcements Must Be Used At The Entry And Exit Points Instead Of The Usual Reinforcing Steel. During The Flush Drilling Work (Lot 1), The Excavation Pit Remains Filled For The Time Being. Only Then Can The Excavation Pit Be Excavated.