EFCO’s High-Load Shoring Supports Cross Beams in Construction of Yellow Line – Bangkok, Thailand

Elevated Monorail

STECON

The Mass Rapid Transit Authority of Thailand (MRTA) under the Ministry of Transport, the Kingdom of Thailand, is implementing the MRT Yellow Line Project, Lat Phrao – Samrong Section using an elevated monorail system. The total distance of this elevated monorail is  18.9 miles (30.4-km) long with 23 stations, and the total investment cost is 55 billion Thai baht (US $1.76 billion). A Joint Venture between BTS Group Holding, Sino-Thai Engineering and Construction (STECON) and Ratchaburi Electricity Generating Holding. EFCO partnered with STECON on this project, providing a strategic plan to achieve the lowest in-place concrete cost.

Elevated CrossBeams for Falsework

Shoring and Formwork System

STECON needed a suitable shoring system and formwork for various elevated crossbeams for this project. The CA5 crossbeam, with dimensions of 10′-6″ 3.20 m.(w) x 74′-6″ 22.70 mm(L) x 11′-6″ 3.50 m(H), is located at the center of the main road. The four corbels at the corners of the crossbeam are located 36′ -2″ (11 m) above the existing ground level.

Inclined Soffit Construction Is Easy With High Load Capacity Shoring System

E-Z DECK Shoring Equipment

EFCO introduced STECON to E-Z DECK®, the adjustable shoring system, for the falsework of a crossbeam. The E-Z DECK Swivel Head supports the Z-BEAM®, which in turn supports the inclined soffit of the crossbeam. This enabled STECON to easily assemble the E-Z DECK shoring equipment without additional wood blocks or steel fabrication. This is an outstanding benefit of EFCO equipment compared with the traditional method used in the market.

Even with the U-head, the E-Z DECK shoring post is still able to maintain the heavy-load capacity of 20 kip (89 kN). This high-load capacity enabled STECON to fully cast concrete at 11′-6″ (3.50 m) height in one pour.

Adjustable Shoring Systems for Concrete Construction

EFCO’s Innovative Designs

Another structure was CA6 crossbeam, which has a similar dimension with CA5, but is located adjacent to the bridge and nearby the canal. EFCO engineering developed an innovative design which uses different post locations on different ground elevations, each with different ground support bearing capacity. Some of the E-Z DECK posts are situated on the contractor’s platform in the canal, a few E-Z DECK towers are sitting on the bridge. Once the E-Z DECK Long Jack is attached to the E-Z DECK Post, it easily turns and adjusts the height between 5″ (125 mm) to 965 mm to meet the varying heights of the inclined soffits. EFCO’s Z-BEAM stringer, which can be connected end to end using EFCO Quick Bolts, enables the Z-BEAM to carry bending moment between each Z-BEAM and acts as a continuous beam to support the loading from the long crossbeam.

Parallel Inclined Formwork

Sloping Side Formwork

EFCO provided E-BEAM® and Z-BEAM for the sloping side formwork. The E-BEAMS were designed to be inclined parallel to the inclined soffit. The benefit of E-BEAMS, which have holes at 2″ (50 mm) centers, combined with Z-BEAMS, which have holes at 4″ (102 mm) centers, is the contractor can connect the different degree of sloping E-BEAM on the Z-BEAM. STECON team was able to easily shape the plywood to fit the actual concrete area of the side form.

Cast-In-Place Concrete

Pier Heads

Most of the typical pier heads in this project are precast, however the long span parts, which is designed to carry the load over the existing obstructions like intersections, bridges, etc., are cast-in-place. Therefore, these cast-in-place crossbeams and hammer head pier caps were the critical part of the MRT Yellow Line construction schedule. EFCO’s engineering plan provided efficiency and the productivity that the customer needed to meet the critical construction schedule.

EFCO’s E-Z DECK Shoring System Is Being Used For Several Pier Caps And Crossbeam

As following:

• 2 bridge piers of Crossbeam CA5: 10′-6″ (3.20)W x 74′-6″ (22.70)L x 11′-6″ (3.50)H with shoring height 36′-4″ (11.07 m).
• 2 bridge piers of Crossbeam CA6: 10′-6″ (3.20)W x 84′-4″ (25.70)L x 11′-6″ (3.50)H with shoring height 39′-8″ (12.07 m).
• 2 bridge piers of Crossbeam CA2: 21′-8″ [(6.59)W x 22′-8″ (6.90)L x 5′ (1.50)H with shoring height 41′-5″ (12.62 m)].
• 2 Hammerhead pier caps YL10-P33,P34 [9′-3″ (2.80)W x 25′-5″ (7.74)L x 6′-7″ (2.0)H with shoring height 48′-11 1/2″ (14.91 m)].
• 13 Hammerhead pier caps YL10:P37-44,P47-51 [7′-7″ (2.30)W x 36′-3″ (11.04)L x 6′-7″ (2.0)H with shoring height = 4.40-11.63 m].
• 7 Hammerhead pier cap YL11:P12-14,P5,P6,P34,P35: [2.30(w) x 10.00(L) x 2.0(H) with shoring height 37′-5″ to 40′-9″ (11.40 to 12.40 m)].

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