Rock Anchors for High and Steep Slope Stability of A Nuclear Power Plant

Time:2022-07-15From:sinorock View:

In engineering construction, geological disasters such as the collapse of high and steep slopes and landslides will bring immeasurable losses to the safety of engineering and workers. Therefore, the reinforcement and protection of the slope are very important.

high slopes of a nuclear power plant

There are various forms of slope protection technology. Generally, the combination of hanging net shotcrete and rock-soil anchorage is mostly used. Self-drilling rock anchor is a new type of support technology, which can meet the requirements of design anchoring force of 50kN~1500kN, and is widely used in slope protection.

Features of Self-Drilling Rock Anchor

T Thread 52 Outer Diameter Self-drilling Rock Anchor

(1) Drilling, grouting, and anchoring are completed at one time. The bolt body as the drill pipe does not need to be pulled out, the hollow of the bolt is the grouting channel, and the grouting is carried out from the inside to the outside. The process is simple and the construction is convenient and quick.

(2) The three-in-one function of the anchor rod can form anchor holes and ensure the effect of anchoring and grouting without special means such as wall protection or pre-grouting during construction under various surrounding rock conditions.

(3) It can be arbitrarily cut and connected and lengthened, which can be applied to a relatively narrow construction space, and realizes the design idea of strengthening the surrounding rock with extra-long bolts.

(4) The high-efficiency grouting plug keeps the grouting at high pressure, fully fills the gap, and consolidates the broken rock mass. The high-strength backing plate and nut evenly transmit the stress of the deep surrounding rock to the surrounding rock of the cave wall, so as to achieve the purpose of supporting the surrounding rock.

Project Overview

The west side slope of the main plant area of a nuclear power plant is a rock slope. Due to the impact of rain erosion and blasting construction, the slope partially collapsed and fell off. In order to strengthen the local stability of the slope, a local protection and reinforcement treatment plan is determined.

(1) Repair of defects: C15 concrete is used to repair the parts where the road collapses and over-excavation is serious, and the vertical transportation of concrete adopts the technology of spraying into the warehouse.

(2) Anchor rod: self-drilling hollow anchor rod anchoring lattice is adopted, the outer diameter of the anchor rod is 27mm, the diameter of the drilling hole is 80 mm, and the length of the anchor rod is 6 m ~ 12 m, all of which are anchors with a standard length of 6 m. The rod connection is extended.

high-slopes-with-broken-and-loose-rock-layers

Key Points of Construction Technology

The construction steps of a self-drilling rock anchor are:

(1) Use the bolt drill to drill the bolt with the drill bit installed to the design depth;

(2) Remove the drilling rig and install the slurry stopper in the anchor hole 25 cm away from the orifice to seal the hole. In special cases such as high grouting pressure or broken surrounding rock, the hole can also be sealed with an anchoring agent.

(3) Connect the tail end of the bolt with the special grouting machine through the grouting quick joint.

(4) Start the grouting machine for grouting, and stop when the grouting is full and the pressure reaches the requirement. The grouting pressure is determined according to the calculated parameters and the performance of the grouting machine.

(5) Install the backing plate and the nut according to the design requirements.

The practice has proved that the construction efficiency of the self-drilling rock anchor is more than 30% higher than that of a traditional grouting bolt. The self-drilling hollow bolt anchoring technology brings great convenience to the treatment of disastrous geological slopes, and it is more advanced, applicable, and economical for the protection and reinforcement of slopes, and has played an irreplaceable effect with other anchoring materials.

Return The List