TYPE | Transportation Infrastructure | LOCATION | Beijing |
MATERIAL | KIN FLAGO DR，KINJOYA PU SYSTERM，KIN PLUME VERDASYS | YEAR | 2021 |
AREA | 18000㎡ |
Background
As Beijing’s first north-south express line, Line 19 traverses the city center, facing complex geology and high groundwater levels, posing significant demands on underground structural waterproofing. The project employed a comprehensive strategy centered on structural self-waterproofing, flexible external waterproofing, and reinforcement of critical details to achieve a “no seepage, no leakage, no damp stains” standard. Phase I runs from Mudanyuan Station in the north to Xingong Station in the south, covering approximately 22.4 km entirely underground, with 10 stations (8 interchange stations). 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
Phase I of Line 19 opened for operation on December 31, 2021. The main structure has experienced no structural leaks, and the operational environment remains dry and stable. The project successfully demonstrated the application of pre-applied reverse-bonding membranes in underground works within Beijing’s core urban area. It provided a replicable waterproofing technical approach and management experience for future subway lines in Beijing.
