In underground construction, such as tunnels and basements, polymer waterproof membranes must withstand hydrostatic pressure and soil movement. Weifang Luyang’s self-adhesive bitumen membranes, infused with polymer modifiers, provide a flexible yet robust seal against groundwater. A tunnel project in Peru’s Andes Mountains faced challenges with water seepage due to fractured rock formations. Our membranes, applied with a cold-adhesive technique, created a continuous barrier, preventing corrosion of reinforcement steel and ensuring structural integrity. The project’s engineer praised the membranes’ ease of installation, which reduced labor costs by 20% compared to traditional methods.