Flexible Rock Bolt Systems for all Requirements: The Chilean Ruta 5

Ruta 5, one of the most important highways in Chile, runs from the border with Peru to the southern city of Puerto Montt. Within the scope of a 300 million US Dollar project, the Ruta 5 Norte section leading from Santiago to the Port of Los Vilos located approx. 230km further north is being widened to create a modern highway.

In the section from km 74 to 79 near Cuesta de las Chilcas, Ruta 5 leads steeply uphill. Here, a viaduct is being built parallel to the current road. The project includes a new lane towards the South, an additional lane uphill for freight traffic and new prefabricated concrete crash barriers on both sides for safe lane separation. The new roadway alignment, with a maximum inclination of 7%, will also curve less and ascend less steeply than the previous road.

The slopes were comprehensively stabilized at the cuts necessary for the new route in order to prevent landslides caused by instability or earthquakes. The difficult geological conditions required long anchor lengths. Furthermore, the installation of the anchor systems had to be carried out on steep hillsides.

In view of these requirements, DSI Chile proposed a combination of self-drilling DYWI® Drill Hollow Bar Systems and massive DYWIDAG and GEWI® Rock Bolts.

To stabilize some areas of unstable rock strata, DSI Chile supplied a total of 3,000m of 12m long, R32 Ø selfdrilling DYWI® Drill Hollow Bar Systems. For anchoring in deeper, load-bearing rock, 25t of 50mm Ø GEWI® Rock Bolts were used. For an additional section, DYWIDAG supplied self-drilling, passive DYWI® Drill Hollow Bar Soil Nails that were installed into the slope in depths ranging from 9 to 35m and injected with grout along their entire lengths.

In the area underneath the loose soil wedge at the surface, a combination of 57t of 32mm Ø DYWIDAG Rock Bolts and self-drilling R51 – 660 Ø DYWI® Drill Hollow Bar Anchors with a total length of 1,160m were used. In some sections, the embankment cuts were stabilized using mesh and 39.5mm Ø friction bolts with a total length of 2,050m as well as 13t of 25mm Ø GEWI® Rock Bolts.

DSI Chile provided competent technical support to the General Contractor in all project sections. Thanks to the versatility of the DYWIDAG Systems, DSI was able to supply suitable products for all requirements to the jobsite just in time.

DesignProductionSupplyTechnical Support

Ministerio de Obras Públicas, Chile

Petrus Consultores Geotecnicos Ltda, Chile