In the design stage of the TIAA MRT noise barrier walls, the existing building distribution surrounding the MRT route were taken into consideration. Simulations of actual operation were implemented to carry out noise simulation test analysis according to the mass transit system traffic noise control standards. The full-frame or vertical noise barrier walls will be installed in the sections with noise level exceeding the standards. In addition, in response to the needs of future urban and rural development, noise barrier bases will be reserved under the entire MRT route.
In 2015, the TIAA MRT System entered the full testing stage. In this stage, simulation results showed exceeding noises in certain route sections from the friction of the EMU wheels against the rail which caused dissatisfactions from nearby residents. The preliminary review pointed out that the noises are caused by the increased wheel-rail gap from constant friction, so the design was considered to be altered to increase wheel-rail anomalies of noise sources by 2.5dB to strengthen the assessment. Results showed that some sections still required adjustment to existing protection or installing additional barrier walls.
Take Taishan Guihe Station (A6) and New Taipei Blvd. & Ming Chi Rd. intersection as an example, Taishan Guihe Station (A6) originally planned to install vertical noise barrier walls but actual simulation results showed that the noise level tested at floors above 10th floor of the adjacent building have exceeded noise control standards. After reviewing the results of the assessment, the design is changed to half-frame noise barrier walls with increased protective height, total length being 101.5 meters. As for New Taipei Blvd. & Ming Chi Rd. intersection, the area was originally planned with no noise barrier walls. However, due to the development of the city and continuous construction of nearby buildings, additional 50–meter half-frame noise barrier walls will be installed after assessment.
During the construction of changing vertical noise barrier walls to half-frame walls at Taishan Guihe Station (A6), the construction team discovered dislocation of the pillar base causing the horizontal frame unable to be successfully attached. After altering the design of the frame joints to meet the existing pattern, the problem of bridging the frame was then resolved.
Early in the planning stage, although taken into consideration of future urban development demands, the base bolts were still pre-buried on both sides of the TIAA MRT viaducts. Since the TIAA MRT routes are not all linear and each connecting viaducts generated expansion joint gap problems, the pre-buried base bolts often encounter dislocation issues which derived follow-up construction difficulties. It is recommended to consider linear factors and uniform distribution of expansion joint gaps between noise barrier wall pillars or base embedded bolts in advance when deciding pre-buried base bolts positions to avoid dislocation issues that may result in problems of cross-docking frame connection and cause extension of construction period and increase in funding troubles.