On Air Now
Heart Breakfast with Jamie Theakston and Amanda Holden 6:30am - 10am
Engineers have started drilling 25 metre boreholes as part of their investigation of the land around Beaminster Tunnel to find the best option for getting the route open again quickly.
A landslide at the tunnel entrance on July the 7th killed two people.
67-year-old Rosemary Snell and 72-year-old Michael Rolfe from Somerset were driving home from a night out in Beaminster when their silver Skoda was buried by hundreds of tons of mud and rubble. They died instantly.
Engineers are now considering several options to reopen the road, including extending the tunnel either temporarily or permanently.
One long-term solution would be to stabilise the hillside using a technique called soil nailing - but this will only work if the underlying ground is appropriate. The stabilisation work would take several months and a temporary shield - effectively extending the tunnel - is urgently being explored.
The temporary shield would have to rest on the existing entrance side walls which may not be strong enough. Engineers are assessing whether this approach is suitable; their report will be available by the end of September.
They will also measure the structure of the hillside to see if the stabilisation option would work. Boreholes up to 25 metre deep will be drilled through the hillside from the top of the ridge, taking soil samples at various depths.
A further alternative could be a permanent extension to the tunnel which might involve replacing the side walls entirely. Engineers are considering the technical challenges of this option toom.
Since 7 July when the landslide blocked the road, engineers have identified the risk of further slips, which has meant the road has had to stay closed while the options are considered.
Local people have suggested a range of solutions, including demolishing the tunnel entirely and creating a cutting through the hillside or a new road round it. These options are also being investigated although they would depend on planning permissions and funding applications which would take several years for agreement.
Director for environment Miles Butler said:
"While I understand that local people want a quick solution, we need to make sure that we carefully consider the alternatives. This requires preliminary work which is now underway. We have a good relationship with our consultants who will provide the information we need as soon as they can."
People will be kept up-to-date with the project through meetings, regular updates to parish, town and district councils and via www.dorsetforyou.com/beaminstertunnel