Case Study: Seismic Performance of Halim High-Speed Station

The previous four parts covered the theory: force-based design, pushover analysis, three methods for the performance point, and performance levels. This final part sums up the results: how the structure of Halim High-Speed Railway Station performed under the maximum considered earthquake, and whether the original design was safe.

The previous part covered structural performance levels.

The Halim Station case study at a glance

Three methods and six earthquake cases gave 18 performance points. A check this thorough was needed because the Jakarta Building Expert Team (TABG) regarded the station as both a building and bridge infrastructure.

Force-based design results

The modal analysis of the original design showed regular behaviour:

• Mode 1: translation in X, period 0.706 s, 83% mass participation.
• Mode 2: translation in Y, period 0.699 s.
• Mode 3: rotation, period 0.686 s.

The first two modes are translations and rotation only dominates the third. This pattern usually indicates a well-balanced structural layout. A seismic response coefficient Cs of 0.0943 and a total building weight of about 10,517 tonnes gave a design base shear of about 9,730 kN.

Performance points: the range across three methods

Across the 18 performance points, base shear ranged from about 465,000 to 648,000 kN and displacement from about 0.07 to 0.10 m. The pattern was consistent: FEMA 356 gave the largest displacement and base shear, ATC-40 the smallest, and FEMA 440 fell in between. Each method is explained in part 3 of this series.

Performance level: Immediate Occupancy

The displacement at each performance point was divided by the total building height to give a drift ratio. Every method and every case gave a ratio below 0.01, at about 0.004–0.006. Against the ATC-40 limits, Halim Station falls in Immediate Occupancy (IO).

For the maximum considered earthquake (2% in 50 years), the minimum target was Life Safety, so Immediate Occupancy exceeds that target. The conclusion holds for the SNI 1726:2012 earthquake used in design as well as for the newer SNI 1726:2019.

Response modification factor R: on the safe side

The original design used a response modification factor of R = 8. The pushover curves allow the R the structure actually has to be calculated for all six earthquake cases (X and Y):

Every R from the analysis is greater than 8. The ductility and reserve strength assumed in design are therefore actually present, and the design with R = 8 is on the safe side.

Plastic hinge pattern: strong column, weak beam

The pushover analysis also shows where damage forms first. At Halim Station, plastic hinges formed at both ends of the beams and at the base of the first-storey columns. This follows the strong column, weak beam principle: beams yield first and absorb earthquake energy while the columns, which carry the whole building, stay intact. The hinges that formed were also within the Immediate Occupancy range.

Why does this matter? If columns yield first, a whole storey can lose its ability to carry the floors above and trigger a collapse. Damage at beam ends is far easier to repair and does not threaten the stability of the whole building.

Tip: When you receive a seismic evaluation report, ask three questions: what performance level was reached, is the R from the analysis greater than the design R, and where do the first plastic hinges form? Those three answers give a fairly complete picture of structural safety.

Study conclusions and lessons for owners

Based on these results, the study concluded:

1. Although designed to SNI 1726:2012, Halim Station reaches Immediate Occupancy under both SNI 1726:2012 and SNI 1726:2019.
2. The initial response modification factor of R = 8 is on the safe side.
3. The plastic hinge pattern shows that the structure meets the strong column, weak beam principle.

In short, the structural design of Halim Station was judged safe and expected to perform well in a strong earthquake.

The lesson for owners: design to SNI is the required baseline, and performance-based design can add a further layer of checking for essential buildings, buildings with combined functions, or older buildings designed to earlier codes. The results still depend on the model and its assumptions, so every building needs review by a competent engineer.

More project facts are on the Halim High-Speed Railway Station page and in the article on the four Jakarta–Bandung high-speed rail stations. For a seismic performance evaluation of your building, contact our team through our structural audit and evaluation service.

This article provides general information. Every project still needs to be analysed and calculated by a competent structural or geotechnical engineer, in line with the applicable SNI codes and regulations.