Houston Methodist Hospital Centennial Tower

The tower’s northwest corner required more than 50 feet of cantilever to preserve ambulance parking, vehicular circulation and headroom while avoiding an existing underground utility that had to remain operational.

The pedestrian bridge spans active roadways and connects to operational hospital facilities, leaving limited space for cranes, staging and temporary support.

The bridge had to connect to Walter Tower without transferring significant additional loads to the existing structure. 

The elevated transfer girder supports columns above while suspending columns and floors below, creating temporary loading conditions that changed as construction progressed.

The transfer girder required substantial post-tensioning and reinforcing within a 27-foot-deep system while accommodating cladding setbacks, construction access and connections to adjacent floor plates.

Engineers located a 53-foot-long cantilevering transfer girder within a mechanical level, using its taller story height to preserve clearance above the ambulance drive. A 68-foot backspan helped balance the cantilevered load and reduce uplift.

The 8,000-psi concrete girder uses approximately 300 post-tensioning tendons to control deflection and reduce reinforcing congestion. Strut-and-tie modeling addressed deep-beam behavior and critical discontinuity regions.

The bridge was divided into smaller assemblies compatible with the available tower cranes. The erection strategy allowed crews to build the bridge incrementally and cantilever it outward from Centennial Tower without conventional shoring below.

Assembly weight estimates, crane capacity evaluations, rigging concepts and temporary stability provisions informed how each bridge segment could be lifted, secured and connected safely during erection. 

Staged construction analysis predicted tower behavior as loads shifted from temporary supports to the permanent transfer girder. Temporary steel supports and sand jacks facilitated controlled load transfer and support removal. 

The structural configuration maintained ambulance access, vehicular circulation and operation of the existing underground utility while supporting the tower above.

Increasing tendon diameter from 0.5 inch to 0.6 inch reduced the required tendon count by approximately 30%, helping manage congestion at anchorages and within the reinforcing cage.

Field monitoring showed that observed transfer-system deflections tracked predicted behavior during early construction stages and remained below predictions as work progressed.

The completed bridge transfers most gravity and construction loads to Centennial Tower, limiting additional demand on Walter Tower.

Segmenting the bridge for tower-crane erection provided a feasible installation strategy where active traffic, underground infrastructure and limited access prevented conventional temporary shoring.