Coal Seam Simulation Mining Test Acquisition SystemCoal SeamMining Roof Collapse Disaster Test Simulation

Coal Seam Roadway Excavation Mining Simulation Test SystemCoal Seam Mining Three-Dimensional Physical Simulation Experimental Device

I. Program Overview

Aiming at disaster situations such as coal and gas outbursts, abnormal gas emissions, and roof collapses during coal seam mining, a three-dimensional similarity simulation test system with dimensions of 2*1*1m (adapted for coal seam thickness of 2.5m and roadway excavation of 4×3m scenarios) is constructed. It simulates roadway excavation conditions at a depth of 500m (vertical/horizontal stress 0-2.5MPa) with an excavation speed of 0.2~0.3m/h. Dynamic data of stress field, displacement field, pressure field, and concentration field are collected to reveal the evolution patterns of gas and pressure during the mining process, providing a basis for disaster prevention and control.

II. Main Technical Parameters

1. Pressure Loading System

Vertical/Horizontal Stress: 0-2.5MPa

Number of Control Channels:

X+ direction: 5 channels, single cylinder rated load 1000kN, total load 5000kN;

X- direction: 5 channels, single cylinder rated load 1000kN, total load 5000kN;

Y+ direction: 2 channels, single cylinder rated load 1500kN, total load 3000kN;

Y- direction: 2 channels, single cylinder rated load 1500kN, total load 3000kN;

Z direction: 5 channels, single cylinder rated load 1000kN, total load 5000kN;

Pressure Accuracy: ±2% F.S

Displacement Control Speed Range: 0.01mm/min-50mm/min

Maximum Stroke: 500mm

Displacement Range: 500mm

Displacement Accuracy: ±1% F.S

Displacement Resolution: 0.1mm

Loading Method: Uniform Hydraulic Loading

Measurement Methods: Stress and Displacement Loading Methods

Oil Source System Pressure: 31.5MPa

Oil Pump Motor Rated Power: 75kW

Oil Pump Motor Rated Voltage: 380V

Equipped with Air Cooling System

Similar Material Box: 2m (length) × 1m (width) × 1m (height)

2. Excavation Speed Control System

Model Excavation Size: 800*500mm

Cutterhead Diameter: φ200mm

Speed Range: 0.2-0.3m/h

Positioning Accuracy: ±0.05mm

Response Time: ≤3ms

Excavation Method: Cutterhead + Fixed Track, Roadway Diameter 0.2m

III. System Composition

(1) Three-Dimensional Box Structure

Main Structure: Similar Material Box: Made of high-strength steel frame with 20mm wall thickness, internal dimensions 2m×1m×1m, reinforced on all six sides with stiffening grids to enhance compressive capacity, capable of withstanding a maximum confining pressure of 2.5MPa. It simulates the pressure environment of a 500-meter-deep coal mine, providing basic pressure conditions for simulating disasters such as roof instability and water inrush.

Stress Loading System:

Loading Method: Hydraulic cylinder loading, automatically controlled during the test, enabling axial force loading and uniform axial pressure loading to simulate the complex stress conditions of the roof and coal seam underground. It works in conjunction with stress-strain monitoring and disaster simulation, and is equipped with a displacement acquisition device to record displacement changes caused by applied forces.

(2) Excavation Simulation Device:

The excavation simulation device is integrated into the three-dimensional box test bench (model size 800*600mm, calculated at a scale ratio of 1:5). It mainly consists of a power drive module, cutterhead rock-breaking module, track guidance module, propulsion control module, and auxiliary monitoring module. Through the coordinated operation of these modules, it simulates the roadway excavation process in coal mines. The excavation speed (0.2 - 0.3m/h), direction, and other parameters can be flexibly adjusted according to test requirements to accurately reproduce excavation operations under different working conditions.

(3) Disaster Simulation System

Coal and Gas Outburst Simulation:

By controlling gas injection volume and pressure, combined with a rapid pressure relief device, gas outbursts are simulated. A high-pressure gas tank (rated pressure 16MPa, volume 50L) and a mass flow controller (0 - 50L/min, accuracy ±1%) are used to inject gas. A rapid pressure relief valve is set to achieve instantaneous pressure relief, simulating the outburst process.

Roof Collapse Simulation:

Vertical cylinders are controlled in groups to simulate roof collapse through local unloading. A weak layer (10mm thick, adjustable strength) is preset at the top of the box. When the corresponding cylinders are unloaded, roof collapse is triggered.