This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-34437920
The article has changed 4 times. There is an RSS feed of changes available.
| Version 1 | Version 2 |
|---|---|
| St Albans sinkhole: Geophysical surveys to find other pits | St Albans sinkhole: Geophysical surveys to find other pits |
| (about 17 hours later) | |
| A geophysical survey has begun under a housing estate where a 33ft (10m) deep sinkhole opened up on Thursday. | A geophysical survey has begun under a housing estate where a 33ft (10m) deep sinkhole opened up on Thursday. |
| Hertfordshire County Council has commissioned the study after the hole, which was 66ft (20m) wide, appeared on Fontmell Close in St Albans. | Hertfordshire County Council has commissioned the study after the hole, which was 66ft (20m) wide, appeared on Fontmell Close in St Albans. |
| A local history society said the Bernard's Heath area was covered in brick makers' clay pits in the 19th Century. | A local history society said the Bernard's Heath area was covered in brick makers' clay pits in the 19th Century. |
| The council has spent the weekend filling in the hole with concrete. | The council has spent the weekend filling in the hole with concrete. |
| About 77,000 litres was pumped into it on Friday with a further 100,000 litres on Saturday. | About 77,000 litres was pumped into it on Friday with a further 100,000 litres on Saturday. |
| It was being left to set on Sunday and the plan was to fill it with another 100,000 litres on Monday. | It was being left to set on Sunday and the plan was to fill it with another 100,000 litres on Monday. |
| 'Minds at ease' | 'Minds at ease' |
| Roger Miles, an amateur archaeologist with the St Albans & Hertfordshire Architectural & Archaeological Society, said brick making had existed for at least 300 years until the early 1900s, when many pits were filled in with the city's rubbish. | Roger Miles, an amateur archaeologist with the St Albans & Hertfordshire Architectural & Archaeological Society, said brick making had existed for at least 300 years until the early 1900s, when many pits were filled in with the city's rubbish. |
| He said clay pits would have exposed the underlying chalk layers to more water, which could have lead to crumbling and fissures. | He said clay pits would have exposed the underlying chalk layers to more water, which could have lead to crumbling and fissures. |
| "According to Ordnance Survey maps clay pits extended very close to where the sinkhole is and many had reverted to woodland over the past century," he said. | "According to Ordnance Survey maps clay pits extended very close to where the sinkhole is and many had reverted to woodland over the past century," he said. |
| "We know the locations of some pits, but there may be others which were never mapped, so we need a fresh study to put householders minds at ease. | |
| "You can get a very good idea of what is under the ground without digging." | "You can get a very good idea of what is under the ground without digging." |
| A council spokeswoman said the survey work would be non-invasive and detecting equipment could be used to pick up any underground anomalies such as weak spots or voids. | A council spokeswoman said the survey work would be non-invasive and detecting equipment could be used to pick up any underground anomalies such as weak spots or voids. |
| She said it could take weeks before the results were known. | She said it could take weeks before the results were known. |
| Once all the concrete was set, it was hoped utilities could be fully restored to the fifty homes which were affected by the end of the week. | Once all the concrete was set, it was hoped utilities could be fully restored to the fifty homes which were affected by the end of the week. |
| No-one was injured when the hole appeared, but five homes were evacuated. | No-one was injured when the hole appeared, but five homes were evacuated. |
| The council confirmed Fontmell Close had been resurfaced a year ago. | The council confirmed Fontmell Close had been resurfaced a year ago. |
| What causes a sinkhole? | What causes a sinkhole? |
| The British Geological Survey says there are several different types of sinkhole, sometimes known as "dolines". | The British Geological Survey says there are several different types of sinkhole, sometimes known as "dolines". |