GB146.2-2020
Gauge for standard gauge railways—Part 2: Structure gauge
标准轨距铁路限界 第2部分：建筑限界
GB 146.2-2020 is a current mandatory Chinese national standard for Gauge for standard gauge railways—Part 2: Structure gauge. It appears in the Construction compliance cluster with a product safety focus and has an implementation date of May 1, 2021.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard applies to the design, construction, and operational maintenance of 1435mm standard gauge railways in China. It specifically covers three operational categories: mixed passenger-freight railways with speeds $v \leq 160$ km/h, mixed passenger-freight railways with speeds $v > 160$ km/h, and dedicated passenger railways. It is mandatory for all new construction and reconstruction projects falling under these categories.
Technical requirements
The standard defines the building gauge as a perpendicular limit cross-section profile that no equipment or buildings (except rolling stock and interacting devices) may intrude upon. It categorizes requirements based on design speed and traction type (internal combustion vs. electric). For $v \leq 160$ km/h lines, it specifies basic building gauges (e.g., Jianxian-1), tunnel gauges, and bridge gauges. For higher speeds ($v > 160$ km/h) and dedicated passenger lines, it introduces updated basic profiles (e.g., Jianxian-3 and Jianxian-4) to accommodate larger dynamic envelopes. Engineers must ensure that all structures, including platforms, signal masts, and overhead bridges, strictly adhere to these defined spatial limits. The standard also details specific clearance rules for electric traction sections, where maximum heights must be calculated based on the catenary structure height, with minimum vertical limits enforced.
Testing methods
Instead of traditional laboratory testing, the evaluation methods involve geometric calculations and spatial clearance checks. The standard provides specific formulas for calculating curve widening amounts ($W_1$ for inner, $W_2$ for outer) based on curve radius, height from the rail surface, and outer rail superelevation. Compliance verification requires 3D geometric modeling to ensure no physical infrastructure intrudes into the defined gauge. Additionally, it specifies the evaluation of horizontal and vertical dimensions starting from the track centerline and the rail surface, including rotational angle calculations for superelevated curves.
FAQs
What types of railways are regulated under GB 146.2-2020?
This standard applies to the design, construction, and maintenance of 1435mm standard gauge railways in China. It covers three main categories: mixed passenger-freight railways with speeds $v \leq 160$ km/h, mixed passenger-freight railways with speeds $v > 160$ km/h, and dedicated passenger railways.
What are the main updates in GB 146.2-2020 compared to the 1983 version?
The 2020 version introduces building gauges for high-speed railways ($v > 160$ km/h mixed traffic and dedicated passenger lines). It also updates platform gauge heights, adds new lower contour lines for tunnels, and removes obsolete appendix figures from the 1983 version. Engineers must transition to the new 2020 parameters for all modern projects.
How does GB 146.2-2020 differ from international railway standards?
GB 146.2-2020 is a mandatory national standard specific to the Chinese railway network. While it shares the fundamental physics of standard gauge profiles internationally, it defines unique boundary contours and curve widening formulas tailored to China's specific rolling stock and operational speeds. Foreign engineers must adhere to this standard rather than ISO or UIC standards when designing for the Chinese market.
The summary above provides a high-level overview of GB 146.2-2020. To ensure complete compliance for your railway infrastructure projects entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 146.2-2020 today to access all detailed gauge diagrams, dimension tables, and curve widening calculation procedures.
Applicability hints
- Type
- Foundational
- CCS
- S04
- ICS
- 93.100
- Competent department
- National Railway Administration
- Technical committee
- National Railway Administration
Relationships
Replaces:GB 146.2-1983