Scholarlink

<p>Pea-gravel grouting (PGG) is a composite material backfilled between segment and surrounding rock of a shield tunnel, requiring balanced mechanical properties and impermeability. However, the practice always faces an issue of the defects of harden PGG with local cavity, less dense or insufficient strength. In this paper, an experimental study was firstly carried out on the grouting slurry to determine its mix proportion by evaluating the workability and density, which showed that the rational <i>w/b</i> = 0.5 and 0.6 with a sodium bentonite content within 5 ~ 15%. A method was developed to simulate the construction process of PGG to cast the blocks with a size of 900&#xa0;mm×500&#xa0;mm×250&#xa0;mm. Using the samples drilled from the blocks, the cylinder specimens with a diameter of 100&#xa0;mm and a height of 200&#xa0;mm were manufactured for testing the axial compressive strength and the modulus of elasticity of PGG, while those with a diameter of 170&#xa0;mm and a height of 150&#xa0;mm were repaired to be the circular truncated conic specimens for testing the PGG impermeability. Results show that whatever the <i>w/b</i>, the axial compressive strength and the modulus of elasticity of PGG decreased while the impermeability increased with the increase of sodium bentonite content. The increase of <i>w/b</i> results in the decrease of mechanical properties and impermeability of PGG. The optimal content of sodium bentonite with different w/b can be selected in a range of 5 ~ 15% regarding for the practical requirements and the economic feasibility and beneficial effect on environment protection. Formulas are proposed for predicting the axial compressive strength and the modulus of elasticity of PGG in practical application.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Preparation and properties of pea-gravel grouting with sodium bentonite for hydraulic shield tunnel

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年7月23日

查看全文
  • Changyong Li,
  • Yabin Yang,
  • Bo Zhou,
  • Kele Wang,
  • Yintao He,
  • Shunbo Zhao

摘要

Pea-gravel grouting (PGG) is a composite material backfilled between segment and surrounding rock of a shield tunnel, requiring balanced mechanical properties and impermeability. However, the practice always faces an issue of the defects of harden PGG with local cavity, less dense or insufficient strength. In this paper, an experimental study was firstly carried out on the grouting slurry to determine its mix proportion by evaluating the workability and density, which showed that the rational w/b = 0.5 and 0.6 with a sodium bentonite content within 5 ~ 15%. A method was developed to simulate the construction process of PGG to cast the blocks with a size of 900 mm×500 mm×250 mm. Using the samples drilled from the blocks, the cylinder specimens with a diameter of 100 mm and a height of 200 mm were manufactured for testing the axial compressive strength and the modulus of elasticity of PGG, while those with a diameter of 170 mm and a height of 150 mm were repaired to be the circular truncated conic specimens for testing the PGG impermeability. Results show that whatever the w/b, the axial compressive strength and the modulus of elasticity of PGG decreased while the impermeability increased with the increase of sodium bentonite content. The increase of w/b results in the decrease of mechanical properties and impermeability of PGG. The optimal content of sodium bentonite with different w/b can be selected in a range of 5 ~ 15% regarding for the practical requirements and the economic feasibility and beneficial effect on environment protection. Formulas are proposed for predicting the axial compressive strength and the modulus of elasticity of PGG in practical application.