海角视频

Malaysia Square Pedestrian Bridge and Circus Road bridge

London, UK

The landmark Grade II* listed Battersea Power Station sits at the heart of a major, multi-phase regeneration project in Central London that is delivering an entirely new mixed-use neighbourhood with homes, shops, cafes, bars, restaurants, leisure venues, offices and over 19 acres of public realm once complete.

As part of the transformational development, 海角视频 provided the engineering design for both the Circus Road Bridge (also called Halo Road Bridge) and the Malaysia Square pedestrian bridge.

Malaysia Square sits next to the Power Station鈥檚 southern entrance. It is one of the primary arrival points from the wider Battersea and Nine Elms area, and the new Underground station.

Integral to this public space are two new bridges, one road bridge and one pedestrian bridge. The bridges are an essential part of how visitors experience their arrival at this iconic landmark. The Malaysia Square Pedestrian Bridge provides access to the Power Station building at the Upper Ground floor level. Together with the larger Circus Road bridge, it delineates the oval shaped focal point of the square.

Challenge

Circus Road Bridge

The design and construction of the Circus Road Bridge presented a range of challenges to the design team, a collaboration of 海角视频 and WilkinsonEyre architects. In addition to the bridge engineering, 海角视频鈥檚 infrastructure team designed the bridge surfacing and drainage.

Battersea Power Station Development Company (BPSDC) required the early delivery of the Circus Road Bridge to a strict programme to provide construction access and later residence access. The bridge was on the critical path for the wider Power Station regeneration, so any delays would have had significant knock-on consequences.

The Circus Road Bridge was to be constructed ahead of significant basement excavations directly below the bridge and ensuring the safety of the structure during these later excavations was critical.

The design would also need to be able to anticipate future transformation works that were not yet designed. This was achieved, with the considered sequencing of construction works essential the project鈥檚 success.

Another key challenge was the vehicle restraining system for the bridges, which would need to be created as a bespoke design, as proprietary systems were not considered to be in keeping with the aesthetic requirements of the regeneration.

Malaysia Square Pedestrian Bridge

For the Malaysia Square Pedestrian Bridge, the key challenge was the creation of a light-weight structure that could be erected in a very constrained site with limited crane capacity. It is a very slender structure, so pedestrian dynamics would need to be a significant part of the design solutions.

Solution

Circus Road Bridge

Circus Road Bridge forms part of the circular road surrounding the Power Station. Initially the bridge was designed in a temporary condition as part of an early works package so that the bridge could be used to provide construction access to the wider development site. The bridge was completed in 2015 and since then it has played a vital role in providing access to both construction traffic and residents of early development phases.

The bridge is formed by a steel-concrete composite ladder deck arrangement with tapering cantilever cross members fabricated from steel plate. The curved superstructure is continuous over five spans, each of 19m giving a total length of 95m and the bridge width is 10m. The twin longitudinal girders are connected to integral steel column piers. The steel columns, approximately 17m long, were constructed by plunging them into single large diameter concrete piles so that the construction could take place ahead of the excavation of future basement levels around the bridge columns.

We managed the design interfaces with all relevant parties to resolve technical queries and safeguard the bridge during subsequent years of surrounding development, including the excavation and construction of podium structures immediately below and surrounding the bridge. Our teams also undertook a risk assessment and engineering design of bespoke bollards with integrated lighting to act as a vehicle restraint system.

The bridge is positioned at the boundaries of three project phases, each with a different contractor and architect, and needed to be incorporated into surrounding podium structures, with three basement levels directly beneath the bridge. Movement joints at all interfaces ensure the bridge remains an independent structure and only the central span is exposed in the final condition providing a gateway entrance to the power station building.

Malaysia Square Pedestrian Bridge

Malaysia Square Bridge consists of three spans connected in an arrangement that resembles the Greek letter pi. The principal east-west span has an overall length of 28m and is intersected by the two north-south spans, each 13m in length. The width of the deck varies with a minimum clear width of 3.7m. The bridge has lighting integrated into the handrails and provision for rigging anchors for hosting special events.

The superstructure comprises a trapezoidal box girder, fabricated from welded steel plates, spanning between new podium structures and the existing power station building. The bridge has no independent foundations and, together with constraints such as cranage limitations, this imposed strict restrictions on the bridge self-weight and construction sequence.

The bridge was prefabricated and delivered to site in five sections. 海角视频 worked closely with the steel fabricator and contractor throughout the design, fabrication construction process.

Prior to the opening of the bridge, the design team partnered with University of Leeds to undertake detailed dynamic testing to measure the real response of the bridge to simulated pedestrian loading. The results demonstrated that tuned mass dampers (TMDs) were not required due to the enhanced damping effect of the deck finishes not accounted for in the codified dynamic analysis. This approach to the dynamic design ultimately improved constructability, delivered cost savings to the client and significantly reduced the embodied carbon of the structure through material savings.

Value

Our experts played a critical role in the successful design and delivery of both bridges.

The work of our multidisciplinary team ensured the ease and speed of construction, allowing the project to meet a strict programme by designing for prefabrication and the use of plunge columns. The early delivery of the road bridge provided a strategic asset to the client to facilitate wider development.

We designed the modifications to the Circus Road Bridge deck to transform it into its permanent condition. This included new surfacing, lighting, vehicle restraint system, fire protection and facade elements to the exposed bridge soffit.

The prefabricated design for the footbridge ensured efficiency of delivery, while our later dynamic testing work with the University of Leeds, provided reassurance of the bridge鈥檚 performance under full pedestrian loading.