The September update on progress towards the A46 Stoneleigh Junction Improvement Scheme.
Overview
Throughout August, work on site has mainly progressed on the new Westley and A46 Bridges along with the new Dalehouse Lane Roundabout, Northbound Off Slip, as well as Stoneleigh Road East and West.
Currently, there is still a 50-mph speed limit in place on the A46 mainline to allow safe working for the new A46 bridge construction. This is an aspect of traffic management which will remain in place for the foreseeable future. Furthermore, there is still a 30mph speed limit on Stoneleigh Road, which runs for the entire site extent and will also be in place for the foreseeable future.
At the end of August, HS2 implemented a road closure on Stoneleigh Road East to install traffic signals at the junction of Birmingham Rd and the B4115. The closure occurred within the Stoneleigh site works at the top of the Northbound On Slip and Southbound Off Slip. HS2 erected a diversion route for drivers wanting to travel to Stoneleigh along Stoneleigh Road East. This closure was lifted in the evening of 2 September 2022.
Progress to Date
Northbound Off Slip Realignment Works
Work has progressed in the period to construct the new alignment of the Northbound Off Slip. With the new alignment for the slip road half complete (with this completed half open to traffic), work has progressed on the second half to decommission the previous slip road and finalise the drainage. A new section of carriageway has been installed which comprises of a new kerb line and a maintenance layby. Road capping and Type 1 sub-base – the first parts of the road foundation – have been installed.
Figure 1 – Northbound Off Slip Progress.
Westley Bridge
Throughout August, work has continued to install the permanent formwork panels which began in July. These are located in between the bridge beams and form the first part of the main bridge deck and will be in the bottom face of the deck so they can be seen from underneath. Each panel needs to be individually lifted in by a crane and guided into place to ensure a tight fit with both the bridge beams and neighbouring panels so it is a time consuming process. By the end of the month, over half of the panels had been installed.
New Dalehouse Lane Roundabout
In previous periods, the Himalayan Balsam bund has been built into the central mound of the roundabout and covered with a geotextile fabric and topsoiled and this is intended to be a permanent feature. Following this, work has been ongoing to lay the remainder of the drainage and install street lighting ducting within what will be the roundabout’s central island. Towards the end of the month, the excavation was being carried out to commence installing the road foundation capping and sub-base. Kerbing has now also begun to be installed for the inner radius of the roundabout.
Figure 2 – New dalehouse lane roundabout progress.
Figure 3 – installation of traffic signal ducts in new roundabout.
New Dalehouse Lane Link
The new Dalehouse Lane link will eventually realign Dalehouse Lane to meet with the new Dalehouse Lane roundabout. In August, the footpath parallel to the new Dalehouse Lane road began its construction with the concrete edgings (which form the back of the path) and Type 1 subbase installed. At the same time, further subbase has been installed into the new carriageway foundation and compacted with a roller. There has also been topsoiling on either side of the new carriageway to complete the earthwork profile. The area is now being prepared for surfacing of the new carriageway which is aimed to take place in early September.
Figure 4 – Installation of type 1 ibaa on new dalehouse lane.
New A46 Bridge
A concrete pour had taken place on the East abutment during July to form the last part of the abutment wall on that side. In August, the shuttering was removed once the concrete has reached sufficient strength as it is important to wait until the concrete has become a stronger solid structure after it was poured to ensure it can support itself as intended once the formwork is removed. This then exposed the concrete surface and the sections of the structure which would end up buried were waterproofed with a liquid waterproofing material. This was a process similarly conducted on the West Abutment.
Figure 5 – Operatives blackjacking the new a46 bridge east abutment.
Stoneleigh Road East Tie In
During the aforementioned HS2road closure, the opportunity has been taken to complete the new road alignment tie in with the existing Stoneleigh Rd East which has only been partially completed. With the benefit of the closure, kerbing can now be installed across the original Stoneleigh Rd East, the first activity of which is to excavate a trench on the line of the new kerbs. The kerbs were then installed on concrete foundations within this trench to form the final finished road alignment at this point. Carriageway surfacing took place at the end of the month took place to allow the road to be open to traffic on 2 September 2022. Figure 6 shows the new kerb line being installed across the original Stoneleigh Rd.
Figure 6 – Carriageway surfacing and new kerb line for stoneleigh road east.
Further Information
As advised previously, from 2 September 2022, there is a new traffic arrangement on Stoneleigh Road East from Stoneleigh to the A46 Northbound On Slip once the HS2 road closure completed. Traffic will now travel two way along this section of road and traffic management and temporary road markings are in place to assist. This arrangement is expected to be in place for the foreseeable future.
Over the next couple of months, work will continue to progress on the Stoneleigh Road West new roundabout, to install the kerbs and complete the new carriageway construction for the roundabout and its 4 roundabout arms. This will include installing Type 1 subbase over the capping, and then eventually the surfacing layers to complete the carriageway construction. The carriageway construction on the Dalehouse Lane Link will be progressed, with the surfacing on the new road to be completed, as well as surfacing and completion of the footways.
On the new A46 bridge, the sheet piles surrounding the concrete abutments to retain the surrounding earth will be removed once the excavations have been filled with backfill material. On Westley Bridge, the installation of the permanent formwork panels will be completed, ahead of the pour of the concrete deck.