A next-generation urban hub

Raising the mega tower

The office tower in Lot 4 (T2) will rise to 370m, set to be the tallest building in the Puxi area. We adopted an efficient ‘moment frame and core’ structural system with two levels of belt trusses following parametric studies at the early stage.

C80 high strength concrete has been introduced to cater for the tower’s exceptionally large floor plate and few numbers of columns, setting a precedent for buildings in Shanghai. Combining with a viscous damper system installed at refuge floors of the tower, the structural performance of the building will be greatly enhanced, whilst keeping column sizes to a minimum.

We used one-story high belt trusses to reduce the frame columns from 16 to 12 at L56 to L57. This high-level transfer system helps tackle the complex challenge of structural irregularity.

We also adopted a performance-based seismic design approach for greater efficiency and economy, and used bored piles with toe grouting to achieve higher pile capacity, supporting this mega tower in Shanghai’s very soft ground.

Creating a deep basement

The T2 tower sits on a 6-level basement – the deepest of its kind in Shanghai. Considering its scale and close proximity to operating metro facilities, a 75m deep diaphragm wall was designed to control the ground movement during excavation and de-watering. The whole operation was carried out in multiple zones and phases to minimise the risk of foundation pit construction while meeting the stringent protection requirements of the Shanghai Metro.

As part of the retail podium in the lot will be constructed over the running metro tunnels, we adopted a ‘surcharge balancing’ approach to remove certain amount of soil above the tunnels and balance it with the weight of newly added building structures.

Utilising digital tools

The curved architectural form and geometry of the tall towers and entrance canopies require close co-ordination between architects and engineers. To this end, we developed a combined digital platform of Rhino and Revit to facilitate the task, ensuring quality construction and seamless integration of the façade and structure.

Revit was especially used in producing all the structural drawings, thus achieving fast turnaround time in design changes, drawing modifications and more precise estimate of structural material quantities.

CAD redevelopment with Python was also used to help enhance the quality and efficiency of print-check works.

Connectivity at large

Embracing a ‘smart, green and integrated’ traffic design, we carried out extensive transport studies and comprehensive review of the six pedestrian footbridges and two internal link bridges to help connect the development with the Xujiahui area and develop an integrated transport hub.

Multi-level pedestrian spaces will form the core of the traffic system with basement levels linking the metro interchange via tunnels and footbridges serving the traffic overground. To evaluate vehicular and pedestrian circulation, we made use of dynamic micro-simulation models generated by Vissim and MassMotion. This helped the government and our client understand the impact and benefits of our proposals.

Smart solutions such as an on-demand car park booking system and robotic car parking facilities have also been introduced to save cost and space.

Minimising noise and vibration

The site is adjacent to the Xujiahui Station, a busy interchange station for three existing metro lines and two future lines, which further complicates the design. Our acoustic engineers made use of in-site tunnel vibration measurement and finite element modelling for detailed analysis of structural vibration and structure borne noise.

We conducted a full range of acoustic analysis including the acoustic criteria, sound insulation design, MEP noise and vibration control as well as environmental noise assessment. A range of mitigation measures were then proposed to achieve high operational standards for the retail facilities and the IMAX cinema.

Shaping a sustainable complex

As the building sustainability consultant, Arup has proposed numerous sustainable features, helping the three grade-A office buildings to aim for LEED Platinum with the hotel tower and retail podiums aiming for Gold certifications.

We increased the proportion of green space in the project and implemented an energy-efficient HVAC system as well as intelligent controls and management systems to enhance the indoor environment. Coupled with the use of reflective roofs to reduce the heat island effect, PV panels will be installed at the rooftop of the office towers to collect solar energy for the buildings’ daily use.

Green construction materials are locally sourced to minimise environmental impacts, while water will be recycled for landscaping, road cleaning and toilet flushing, saving 55% of water annually. Low-emitting, recycled and regional materials will also be used.