TYPE | Transportation Infrastructure | LOCATION | Beijing |
MATERIAL | KIN FLAGO DR，KINJOYA PU SYSTERM，KIN PLUME VERDASYS | YEAR | 2019 |
AREA | 68000㎡ |
Background
The Beijing Metro New Airport Line serves as the “air corridor” connecting the city center with Daxing International Airport. It is not only a key artery for Beijing-Tianjin-Hebei integrated transportation but also a major underground project facing multiple challenges like high water pressure, water-rich sandy cobble strata, and small-radius curve tunneling. Its waterproofing system employed a three-tier defense, with structural self-waterproofing as the base, flexible external waterproofing as the core, and sealing of critical details as the focus, aiming for a 100-year, “watertight” structure. KINJOYA was responsible for waterproofing one station and its associated tunnel section.
Solution
This project primarily used KIN FLAGO DR HDPE pre-applied waterproofing membrane. For the station roof slab, a composite system using KINJOYA PU polyurethane coating and KIN PLUME VERDASYS PVC root-resistant membrane was employed. The KIN FLAGO DR HDPE membrane utilizes a pre-applied, reverse-bonding method, where its adhesive layer forms a chemical bond with the fresh concrete, integrating the membrane with the structure. For the roof slab, KINJOYA PU coating provides a continuous, seamless film with excellent elasticity and adhesion. The KIN PLUME VERDASYS PVC membrane offers superior root penetration resistance, durability, and weatherability. In the tunnel, the segment joints, a critical waterproofing point, were further reinforced in high-risk sections using specialized joint sealants supplied by KINJOYA, enhancing the watertightness of the segments.
Outcomes
The project successfully achieved safe tunneling through high-water-pressure, water-rich strata without major leakage incidents. It provided a technical benchmark for waterproofing design for high-speed, long-distance underground lines. It promoted the large-scale application of pre-applied reverse-bonding technology and coating composite systems in the rail transit sector. The robust waterproofing supports the efficient operation of the Daxing International Airport transportation hub, contributing to the national strategy of coordinated Beijing-Tianjin-Hebei development.
