1. Plastic Drainage Board Specifications and Functions

Plastic drainage boards, also known as SPB-A, B, C, and D series geosynthetic drainage strips, are an effective vertical conduit for saturated cohesive soils like silt, silty soil, and fill material, facilitating consolidation through drainage methods. This significantly reduces consolidation time. In soft soil foundation treatment, the design and construction equipment for drainage boards are largely similar to those for sand bag wells.

II. Structural Indicators

Plastic drainage boards are a strip composite structure, made from high-pressure polyethylene. The core plastic board, extruded in the middle, consists of 35 ribs and 34 grooves, forming the skeletal and channel structure of the drainage board. The cross-section is an interconnected cross shape, with a width of 100 ± 2mm and a thickness of 3.5 - 6.0 ± 0.5mm. The outer layer is wrapped with a fiber nonwoven fabric, serving as a soil separator and filter membrane.

Key Indicators: Composite tensile strength, elongation, longitudinal water permeability, membrane permeability coefficient, wet sample tensile strength, dry sample tensile strength, etc.

Section 3: Specifications of Plastic Drainage Boards

Type A: Suitable for depths less than 15 meters.

2. Type B: Suitable for depths less than 25 meters.

3. C Type: Suitable for depths less than 35 meters.

4. D Type: Suitable for depths less than 40 meters.

Based on different depths of soft subgrade, the products are divided into four types: A, B, C, and D, in accordance with the JT/T521-2004 industry standard released by the Ministry of Transport of the People's Republic of China in 04-16.

Technical Specifications: