The project Captacion de Agua de Mar de San Pedro del Pinatar - a quatum jump in microtunnelling
Dec 14, 2006
This microtunneling project presents the internationally longest driven drilling length with DIN 2000 AVN in case of landoutfall. Particular challenges in this project were: length, geological conditions, time factor, and annulus lubrication.
The project on the Spanish shore included the construction of two pipelines to a seawater demineralisation plant. In the future 24 million cubic meters of sea water shall be supplied to the plant. The drilling project started in September 2005. The European Union supported the project by financing about 85 % of the construction sum. The total construction sum of the network amounted to 83 m €. The company DRAGADOS/FCC – SPAIN – was in charge of planning the ambitious project; the undertaking company was Sonntag Iberica. Dieter Bücher/Firma Dieter Bücherl Spezialtiefbau Amberg managed the construction from planning to finishing. Already in the planning phase the company BAROID IDP EUROPE had been entrusted with building a mud programme by which drivage in these dimensions would become feasible. Here, the main point was the annulus lubrication.
The automatic full-face cutter Herrenknecht AVN was used which had been modified for this particular application. The press capacity of the plant amounted to 1,200 tons. Here, an automatic annulus lubrication was very essential for this project. A separation plant equipped with mud screens and hydrocyclones provided by the company Schauenburg allowed a fast and clean preparation up to a cut point of 40,000 mm. The MAB performed 400 cubic meters per hour. The company Gollwitzer supplied the ferro-concrete drivage pipes (inside: DN 2000, outside: DN 2400). Intermediate jacking station provided by the company Gollwitzer were inserted along the drift.
According to the geological experts’ reports cross beddings of very different geology were expected in the subsoil: coral beds, sea salt licks, sand, loam, and silt. Especially at the end of the drift the occurrence of some possibly disturbing contaminants such as calcium salts and magnesium salts should be assumed due to the low lapping.
As a result of the inhomogeneous geological conditions and the contaminants to be expected it was necessary to develop an annulus lubrication that would resist all influences possible, especially the time factor. The fresh water for preparing the mixture of the lubrication suspension proved to be a first problem: the surface water which was taken from a little river was of insufficient quality when being used as the basis medium for an optimum annulus lubrication. The pH-value was 5.8; measurements of the German hardness revealed values of more than 25 degrees. Even the drinking water from the local network could not be used without pre-treatment.
Soda Ash + TUNNELGEL PLUS + NO SAG + PAC L + DINOMUL 2 kg Soda Ash were used to make the water user-friendly: the pH-value was increased to 8.5. After the treatment also hardness had optimum values. TUNNELGEL PLUS was the selected bentonite. It had already proven to be the best drilling bentonite in many problematic HDD drillings. NO SAG was used in order to essentially increase the gel strengths of the suspension. Furthermore, NO SAG stabilizes the suspension in the drilling in brackish water or salt water. PAC L should gain control over the contaminants to be expected. Furthermore, DINOMUL was added – a fluid additive that had been developed to reduce the rotation torques and stresses in the drill pipe. By the lubrication of a product pipe DINOMUL also reduces the traction in the HDD procedure. In addition, DINOMUL improves the stability of the borehole by forming a compact thin filter cake and protects reactive formation clays. The product DINOMUL also serves for increasing the lubrication effect in waterbasic muds and counteracting a sticking of the drill string. Experience has shown that DINOMUL can reduce the frictional forces by up to 60 %. In the present Microtunneling project the necessary thrusting forces were lower than 0.1 tons/m2 of the lateral surface. For the whole tunnelling about 1 cubic meter suspension per meter was needed for pumping. The maximum thrusting forces amounted to 600 tons, three of the 15 intermediate jacking stations were used for releasing the casing string only.
More News and Articles
Jul 24, 2024
News
UK utilities place multiple orders for settlement tank technology
Northumbrian Water, Southern Water, and Dŵr Cymru upgrading wastewater sites
Three UK water utilities have agreed orders for the installation of a total of six conical settlement …
Jul 22, 2024
Article
Reusing wastewater, rethinking water: Maharashtra's roadmap
How Maharashtra turns wastewater into a resource
Water resource management is a critical issue globally, and in India, the state of Maharashtra is pioneering efforts to regulate and …
Jul 19, 2024
News
Kansas City advances fire hydrant leak detection technology
An acoustic fixed-base pipe monitoring technology that uses fire hydrants to host multi-sensor devices, has already found more than 30 leaks for Kansas City Water, says Lou Rossetti …
Jul 17, 2024
News
When two bores right a wrong
The Edge Underground team is adamant: there is always a risk of things going wrong on a trenchless project, even for the most prepared contractor.
Experience and having the right equipment can be the difference between …
Jul 15, 2024
News
Adapting to a region’s growing water and wastewater needs
Gippsland Water has completed two major projects to provide local communities with water security. Trenchless Australasia takes a look at the two projects helping increase water supply …
Jul 12, 2024
News
Connections made in Glastonbury
Difficult ground conditions called for a specialist solution when new PE pipes for potable water services had to be installed underneath two, 10-metre road crossings in the grounds of the UK’s ultimate music festival …
Jul 10, 2024
Article
The Water-Energy Nexus: Interdependence and Challenges
Niclas Andersson, CEO of AirWater2All, explains the connection between water and energy. The importance of this connection and the areas in which it needs to be considered are explained …
Jul 08, 2024
News
Minimising cultural impacts with trenchless technology
Yarra Valley Water is leveraging the benefits of trenchless technology to lessen impacts on the Upper Darebin Creek branch sewer project.
The project consists of building a 2.7km sewer pipe …
Jul 05, 2024
News
SprayWall: Reinforcing Underground Infrastructure with Unmatched Strength
In the trenchless technology industry, finding a rehabilitation solution that offers ease of installation and exceptional structural integrity is paramount.
For three decades, …
Jul 01, 2024
News
“Don’t let stereotypes hold you back”
Trenchless Australasia sat down with Rob Carr project manager Marie Piette to discuss her career and work at the microtunnelling contracting company.
From Norway to Cambodia and now Perth, Western Australia, …
Jun 28, 2024
News
Transforming Wastewater: Towards Climate-Neutral Sewage Treatment
Baden-Württemberg’s Minister President Winfried Kretschmann recently toured the Büsnau Training and Research Sewage Treatment Plant, where a pioneering project led by researchers …
Jun 26, 2024
News
Bothar advances with significant new contracts
Having commenced work on the Fitzroy to Gladstone Pipeline earlier this year, Bothar Boring and Tunnelling has announced the award of further contracts as part of its ongoing collaboration with …
Contact
Ulrich Schröder
Sales & Service Europe
Phone:
+49 (0) 2761 838119
Fax:
+49 (0) 2761 839993