{"id":5851,"date":"2026-03-17T12:59:35","date_gmt":"2026-03-17T12:59:35","guid":{"rendered":"https:\/\/mairie-montataire.fr\/?p=5851"},"modified":"2026-04-09T07:39:42","modified_gmt":"2026-04-09T07:39:42","slug":"closure-of-theannee-des-marronniers","status":"publish","type":"post","link":"https:\/\/mairie-montataire.fr\/en\/actualites\/fermeture-de-lannee-des-marronniers\/","title":{"rendered":"Closure of the all\u00e9e des Marronniers"},"content":{"rendered":"

Update - 17 March 2026<\/mark><\/h2>\n\n\n\n

Half-level opening of the all\u00e9e des Marronniers<\/strong><\/h3>\n\n\n\n

The all\u00e9e des Marronniers is once again open to half-lane traffic in the downhill direction.<\/p>\n\n\n\n

The first stage of the works involved rebuilding the collapsed section, making it safer and enabling traffic to flow again.<\/p>\n\n\n\n

A second series of works will complete the project. Dates will be announced shortly.<\/p>\n\n\n\n

Update - 4 March 2026<\/mark><\/h2>\n\n\n\n

First stage of work on the Chestnut Tree Lane completed<\/strong><\/h3>\n\n\n\n
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The first stage of the work on the all\u00e9e des Marronniers is nearing completion. It involved rebuilding two sections of collapsed wall and reinforcing the hillside wall (petit ch\u00e2teau) at the point of the largest collapse.<\/p>\n\n\n\n

During work on the wall, cavities were discovered several metres behind the structure, calling into question the wall's consolidation calculations. New investigations were carried out to determine the volume of the cavities, which have now been filled in.
The very high walls and the presence of a drinking water pipe belonging to ACSO meant that armoured excavations had to be used to avoid destabilising the entire pathway. The retaining walls of both sections were then rebuilt.<\/p>\n\n\n\n

For the first section of the works, form removal is underway, followed by backfilling, which has already been completed for the second section. The next stage will be to build the pavement structure, install the barriers and crash barriers, repair the pavements and finally clean up the site.<\/p>\n\n\n\n

The progress of the works and the announcement of the resumption of traffic, initially on the dual carriageway and in one direction, will be monitored on the town's website or networks.<\/p>\n<\/div>\n<\/div>\n\n\n\n

Update - February 2026<\/mark><\/h2>\n\n\n\n

Information on the complexity of the work on the avenue des marronniers.<\/strong><\/h3>\n\n\n\n

In the context of the dispute with the previous companies that had carried out the work, the court's expert opinion required the premises to be kept intact, with no possibility of carrying out the work.<\/p>\n\n\n\n

After the expert appraisal, they began in December 2025.<\/p>\n\n\n\n

The works involve rebuilding two sections of collapsed wall and reinforcing the hillside wall (petit ch\u00e2teau) in line with the largest collapse (photo 1).<\/p>\n\n\n\n

When the wall on the \u00abpetit ch\u00e2teau\u00bb side was reinforced, cavities were discovered several metres behind the structure, calling into question the wall's consolidation calculations. New investigations were carried out to determine the volume of the cavities and to consider the possibility of filling them.<\/p>\n\n\n\n

During this period, the contractor and the project management team reorganised the tasks to limit the impact on the duration of the works.<\/p>\n\n\n\n

The very great height of the walls and the presence of a drinking water pipe belonging to ACSO (serving several towns) meant that armoured excavations had to be carried out to avoid destabilising the entire pathway. This phase has been completed on the first collapse, and construction of the new wall can now begin (photo 2).<\/p>\n\n\n\n

The cavities are currently being filled in, and work has just begun on shoring up the embankment of the second section.<\/p>\n\n\n\n

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Photo 1<\/em><\/p>\n<\/div>\n\n\n\n

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Photo <\/em>2<\/p>\n<\/div>\n<\/div>\n\n\n\n

Update - July 2025<\/mark><\/h2>\n\n\n\n

3 questions to the Mayor about the all\u00e9e des Marronniers<\/h3>\n\n\n\n

Where do we stand technically, and why do the procedures seem to be taking so long?<\/h4>\n\n\n\n

Indeed, and I deeply regret this state of affairs, since the collapse of a retaining wall and the threats to the pavement in the all\u00e9e des Marronniers last February, we have been required to carry out a number of studies.
It's obviously not our departments that are at fault, but as we can see in this case as in others, no one wants to take responsibility any more, and studies have to be carried out on the soil, materials, altimetry... to confirm the previous studies.
Of course, you have to protect yourself against any problems that might arise, but at some point you have to stop studying and start repairing.<\/p>\n\n\n\n

In concrete terms, today...<\/h4>\n\n\n\n

The firm commissioned to draw up a schedule of works to be carried out has produced an initial report, which it will have to revisit, since the order from the municipality is very specific: work is due to start at the end of September or the beginning of October at the latest, so that the Chestnut Tree Lane can be reopened by the end of 2025, even if only as a half carriageway (in one direction only).<\/p>\n\n\n\n

How do you manage this claim financially?<\/h4>\n\n\n\n

It should be remembered that the town, on the basis of a study carried out by a consultancy firm, carried out work on the retaining walls in 2022-2023 at a cost of \u20ac800,000, and that it was in or near this area that there was a landslide, also linked to bad weather.
We're working on challenging both our insurance and the firm that advised us, but obviously if we wait for the outcome of these actions, the avenue des marronniers will reopen in 4, 5 or 6 years' time. At its meeting on 26 May, the Town Council therefore decided on an initial budget of \u20ac500,000 (part of which will go towards the compulsory studies!) and we will then add to the \"bill\", which is likely to reach \u20ac800,000. Fortunately, the town has very little debt.<\/p>\n\n\n\n

What temporary solutions can be found to improve traffic flow?<\/h4>\n\n\n\n

In truth, the topography of our town, with the hillside and the Th\u00e9rain valley, leaves us with few, if any, options. Whether going downhill or uphill, the all\u00e9e des marronniers is a strategic route.
Some residents have told us about the \"lateral path\" between AKZO NOBEL and the railway line from Montataire station, which would link up with the departmental road. Of course we've thought about it, but on the one hand we don't own the road, and it would cost hundreds of thousands of euros to repair it. Together with the ACSO (Greater Montataire area), we're planning to do this as part of the re-industrialisation of the Marinoni\/Goss site, but as you can see, it will take a few more years.<\/p>\n\n\n\n

I understand the impact that the extra time spent in traffic jams can have on everyone's daily lives. We're always running. For some of us, the pace is already unbearable with our tightly organised schedules. But I want you to know that we are doing everything we can to get the All\u00e9e des Marronniers back into operation, within the means at our disposal and above all with the certainty that the safety of everyone - motorists, pedestrians and local residents - is guaranteed. I hope that it will be reopened by the end of the year.<\/p>\n\n\n\n

Update - May 2025<\/mark><\/h2>\n\n\n\n

Legal expertise and recommendations<\/h3>\n\n\n\n

A expert appointed by the Amiens Administrative Court<\/strong> confirmed that the driveway was dangerous. He asked that she remains closed to cars and pedestrians<\/strong>and a in-depth geotechnical study (mission G5)<\/strong> be carried out to understand the causes of the collapse.<\/p>\n\n\n\n

Safety measures in place<\/h3>\n\n\n\n

In parallel with the study, the municipal services have taken a number of safety measures:<\/p>\n\n\n\n