Hotel in Chongqing

Building use

Hotel

Country/Region

China

Overview

Composite beams, SRC columns, and walls were adopted to reduce component sizes, reduce structural self weight, and reduce earthquake response, while also improving the structure seismic performance.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2019
Number of stories: 75
Gross floor area: 200,000m2
Adopted design code: JGJ99-98; JGJ3-2010; GB50017-2003; GB50009-2012
Engineer(s): Arup
Contractor(s): the 3rd Bureau of China State Construction Engineering Corporation

Issue and/or innovation

This innovation uses a shear energy dissipater with a “structural fuse” +a out-trigger truss system composed of reinforced concrete and steel structures. Compared to the traditional concrete or steel structure out-trigger system, the combined structure form of concrete+ steel out-trigger is adopted, and a shear energy dissipation component is added between the out-trigger and the outer frame column as a “structural fuse”.

Reason for composite solution

To reduce component sizes, reduce structural self weight, and reduce earthquake response, while also improving the structure seismic performance.

Specific solution/technical details

The new hybrid outrigger system mainly composes of the following parts:
– RC outrigger wall: The full storey height RC wall, extending from the corewall, provide the high stiffness while the use the embed steel or rebar bracing improve the wall’s shear capacity.
– The enlarged ring-beam: The top and bottom of the RC wall are thicken to form a ring beam, like a I-section, to allow direct force transfer such to protect the core wall as well as to facilitate the heavy rebar fixing.
– The steel outrigger truss: bracing connect between the “fuse” and the outrigger wall.
– The eccentrically-braced frame (EBF) link: during seismic events, the EBF link between the mega column and steel truss is to act as a structural “fuse” by yielding at controlled demand levels and limit the damage in the outrigger wall (through its shear deformation and energy dissipation of the ground motion input). The “fuse” are protector of key structural element from extreme events.

The strength ascended from the fuse to reinforced concrete core wall:
– The fuse is designed to be elastic under wind load and frequent earthquake, and dissipate energy at yield stage under Level 2 and Level 3 earthquakes.
– Steel diagonal has higher performance objective than fuse, which is non-yield under Level 2 earthquake.
– Concrete wall outrigger has higher performance objective than fuse and steel diagonal, and should be elastic under Level 2 earthquake.
– Concrete core wall has the highest performance objective, which is non-yield under Level 2 and Level 3 earthquakes. The whole outrigger system is an important structure of protecting core wall as an effective entity.

Impact or effectiveness

Save cost and construction period (Save 40 million yuan in cost and 2 months in construction period)

References / Technical Papers Content

[1] Liu Z G , Hou X Q , Zhu L G , et al.2015.”The Seismic Isolation Design of Sky Conservatory in Raffles City Chongqing” J. Jianzhu Jiegou Xuebao/Journal of Building Structures, 45(24):9-16. [2]Zhu L G, Liu J., Dong X, et al.2015. “Application of innovative hybrid outrigger system in north towers of Raffles City in Chongqing”J. Building Structure. 45(24):7.