The works, needing small controlled blasting, are due to safety problems requiring urgent attention to prevent accidents.
Next week, the Port Authority of Bilbaowill commence the stabilisation works on the old Punta Lucero quarry in the Port of Bilbao whose aim is to stop the landslides and rock falls that have been occurring over recent years.
After the undertaking of several studies and receiving assessment from specialised firms, it was concluded that the only technically effective and lasting way to guarantee the old quarry’s stability was by “combing” the area, from the highest to the lowest levels, by small, controlled blasting and other auxiliary works.
The works will last 30 months, and companies in the zone will be informed 48 hours in advance of the exact dates when blasting (some 15 to 20 times a month) will take place. The first blasting operation will take place on 30 November. The exact time will be confirmed two hours in advance on the day in question; in addition, for each blast, a pre-warning will sound for those port facilities near the works area, which will also be heard in some neighbourhoods of Zierbena. The works will be supervised by the Basque Government Direction of Energy, Mines and Industrial Administration.
The blasting technique to be used is the same as that employed on Road BI-625 where it links with Motorway AP8 at the Arrigorriaga–Zaratamo connection, and that in the Old Quarter of Toledo.
Bearing in mind the technical, environmental and economic advantages – and given that they coincide in time – this project has been included inside the Central Pier Project, whose total budget is 79 million euros. The European Commission will contribute 20% of the overall costs as part of the Connecting Europe Facility (CEF) Programme, with the rest coming from the Port Authority’s own funds. Approximately 15% of these costs correspond to the quarry stabilisation works.
The old Punta Lucero Quarry in the town of Zierbena was exploited from the 1970s until about 15 years ago to provide material for the Extension Works of the Port of Bilbao. Since then, nothing has been extracted, as borrow required for port infrastructures has been obtained either from commercial quarries near the Port, or from other nearby works.
The quarry mainly looks stable and does not pose any problems except in one very specific area due to the position and slant of rock slabs and the constant progressive deterioration
resulting from rains and temperature. Landslides in this area forced the closing of the road beneath for safety reasons, as well as the placing of concrete blocks to prevent rocks rolling down the side from reaching the petrochemical deposits.
These measures were provisional, and actions had to be taken in order to offer a permanent solution to the area by providing the necessary safety for the correct development of port activities for both lorry traffic along the road and liquid bulks storage.
After considering the facts, it was decided to make a pre-study of the affected area and to develop it later so as to establish the alternatives that would stabilise the slope, bearing in mind factors such as safety and durability. The alternatives of embedded anchors and gridirons were rejected due to their bad medium- and long-term performance, and it was decided to undertake stabilisation by creating a new profile with the incorporation of slopes and berms that will serve to guarantee, as mentioned above, long-term safety and durability. Such “re-profiling” will produce a surplus of material that is to be withdrawn and deposited elsewhere.
Since the urgency of this work coincides with the commencement of another work inside the Port, that is, the construction of a new pier needing material from outside for its completion, it has been decided to take advantage of the excess material from the quarry stabilisation works by using it for filling on the new pier, thus benefitting both works. Consequently, all excess material from Punta Lucero will be destined to cover part of the needs on the Central Pier.
Hence, although they are different, both projects were tendered out and awarded in a single public tender. Among the advantages of coordinating the works are the following: both are carried out by the same contractor; economic resources are optimised, including the European subsidy; and the induced conception of significant environmental improvements such as minimising lorry traffic in the surrounding towns.