mikec1972
Civil/Environmental
- Jun 4, 2003
- 6
I have to widen an existing tarmac rural road from 6 to 7.5m over a length of 200m. Being rural the road has no existing gullies or piped surface drainage. The drainage for the road is just over the edge into a grass verge with no positive fall or outfall point, the verge is up and down so rainwater must just infiltrate away. If i was to widen the road i would need some form of roadside infiltration the local authority have suggested some form of stone filled trench within the verge to prevent standing water in the verge almost like a french drain but with no pipe in the base as we do not have an outfall point. My only concern is that by providing a stone filled trench adjacent to the road this may affect the sub-base/capping of the road and invite infiltration of the sub grade. We don't have any room for soakaways so does anyone have any ideas or a detail i could adopt? Also in widening the road by 1.5m would you advocate concrete instead of the base and sub/base capping layers or would you go with bituminous full depth construction, if we were to have concrete then would we need any joints as we would be having a 200m by 1.5m concrete strip? Thanks in advance
