Ny Uttigen grunnvannsbrønn

Wasserverbund Region Bern AG (WVRB AG) commissioned the construction of a new groundwater well in Uttigen. This project included the creation of the intake structure and a DN 800 mm siphon line linking the new intake to the existing unification structure. Additionally, two pre-warning points were established to monitor water quality effectively.

Brønnsjakt og filterstrenger

The initial phase involved constructing the access slope and drilling subgrade, followed by the construction of a well shaft using overlapping bored pile walls of 24 piles, each 15.0-18.0 meters long. These piles were mostly installed in groundwater due to the near-surface groundwater table. After excavating the well shaft with a cable excavator, it was sealed with underwater concrete to allow the dry construction of twelve horizontal filter strings, each 35.0 meters long.

Betongkonstruksjon og rørlegging

Next, the bottom slab inside the well shaft was concreted, and the cast-in-place concrete casing structure was constructed in several stages. This involved building a circular concrete structure with a basement and first floor by excavating the pit and removing piles down to the bottom slab. Concurrently, walls and slabs were formed, reinforced, and concreted, while siphon and service lines were laid and inserted into the structure, utilizing a working scaffold for the concrete work.

Terrenggjenvinning og tilkobling

After completing the concrete work, backfilling and terrain restoration took place. A 205-meter-long connecting pipeline, designed as a siphon pipeline with a 3 per mille gradient, was constructed to feed the captured groundwater into the WVRB AG network. The pre-warning points required laying KSR lines and installing distribution boxes with cable basements. Eventually, the construction area was restored to its initial state.

Spesialarbeider og utfordringer

The project involved special civil, pipeline, concrete, and pavement construction as well as surrounding works. Significant challenges included working in a groundwater protection zone and managing construction in groundwater. The in-situ concrete construction of a white tank and round shuttering required special techniques, and training was given by KAMIR command for handling unexploded ordnance in the construction area.

Prosjektgjennomføring og kostnader

The project was executed as an ARGE joint venture by ARGE Horibrunnen Uttigen c/o Implenia Switzerland Ltd, Wattenwil. It started in August 2021 and was completed in May 2023. The total construction volume was valued at 2.7 million CHF (2.9 million USD). The project was built by Diggelmann + Partner AG as the civil engineering firm, and the building owner was Wasserverbund Region Bern AG.