4results about How to "Increase the internal friction angle" patented technology

The invention discloses a slope cropland soil solidifying material based on agricultural waste and a preparation method thereof, and the slope cropland soil solidifying material is prepared from the following raw materials in parts by weight: 150-200 parts of a calcium lignosulphonate solution, 150-200 parts of a vinasse urease bacterium solution, 15-20 parts of phosphogypsum, 3-5 parts of urea, 2-3 parts of magnesium nitrate, 2-3 parts of calcium hydrophosphate and 2-3 parts of potassium carbonate. Wherein the calcium lignosulphonate solution is obtained by alkali treatment of corncobs, and the vinasse urease bacterial liquid is obtained by two-stage fermentation of corn vinasse with bacillus amyloliquefaciens and bacillus pasteurii. The prepared slope cropland soil solidification material can effectively utilize agricultural wastes, and can improve the soil structure and soil fertility and promote the growth of slope cropland plants while reducing water and soil loss.

The invention provides a soft rock roadway construction method which comprises the following steps that a hole is drilled in a preset position of a soft rock roadway, one end of a steel pipe is driven into the drilled hole, the other end of the steel pipe is fixed to a supporting anchor rod, and a pipe shed pre-supporting system is formed; a comprehensive heading machine starts to work at the bottom of the soft rock roadway, rock mass in the soft rock roadway is excavated from the bottom to the top of the soft rock roadway, and the contour of the soft rock roadway is formed; hollow grouting anchor rods are adopted, grout is injected into the anchor rods, and the soft rock roadway is reinforced; primary concrete spraying is conducted on the section of the soft rock roadway at the first preset distance of the lagging tunneling working face, secondary concrete spraying is conducted on the section of the soft rock roadway at the second preset distance of the lagging tunneling working face, a concrete terrace is poured, and construction of the soft rock roadway is completed. The problem that in the prior art, due to the fact that the strength of a supporting body in a soft rock roadway is limited, the roadway is in an unstable state is solved.

This invention provides a slope protection material composed of recycled heavy metal tailings and its preparation method. The material includes: recycled heavy metal tailings treated with a heavy metal chelating agent as a heavy metal ion capture agent, the chelating agent being added at 0.05%–0.2% of the heavy metal tailings weight; recycled heavy metal tailings as aggregate, which is mixed with natural soil to form a base material at a ratio of 1:1.5–2.5; fine aggregate and fine sand, added at 5%–10% of the base material weight; and high-viscosity industrial-grade sodium alginate added as a water-retaining and reinforcing agent, added at 0.5%–2.0% of the base material weight. Additionally, 28% organic matter is added to the base material. The application of this invention effectively solves the problems of ineffective utilization of recycled heavy metal tailings and excessive use of scarce natural soil in existing technologies, and also addresses the issues of weak strength, poor effectiveness in steep slope treatment, and poor stability in existing slope protection materials.

The invention discloses a dark-excavated large-span column-free underground structure and a construction method for rock-soil strata, and relates to the field of underground engineering technology. The method comprises the following steps: step S1, constructing a plurality of upper transverse guide holes longitudinally above a tunnel vault, using the upper transverse guide holes to preliminarily perform vertical or oblique reinforcement treatment on the rock-soil within the tunnel vault and side wall range, and after the reinforcement range reaches the strength requirement, constructing transverse connecting beams inside all the upper transverse guide holes, and reserving oblique holes in all the transverse connecting beams and all the upper transverse guide hole side walls; using the upper transverse guide holes, transverse connecting beams, transverse frame beams and two obliquely tensioned prestressed anchor cables, etc., the transverse guide holes and the structural members and rock-soil within the tunnel vault range are formed into a whole, the upper load is resisted, and the bending resistance of the overall force system is ensured, and the cohesion and internal friction angle of the rock-soil between the upper transverse guide holes and the transverse frames ensure the shear resistance of the overall force system.