﻿ 三软沿空掘巷合理护巷煤柱宽度研究

# 三软沿空掘巷合理护巷煤柱宽度研究Study on Reasonable Width of Gob-Side Entry Driving in Three Soft Coal Seam

Abstract: Using the FLAC3D numerical simulation method, the stress and displacement distribution of sur-rounding rock for the three soft coal seam were analyzed during driving and coal winning period when the different width coal pillars to protect roadway were placed under gob-side entry driving condition. Based on the analysis results, reasonable width of protecting roadway coal pillar was selected. The research results show that the coal width had little effect on the greater vertical stress in entity coal side and the greater vertical stress in coal pillar side increased with the width of coal increasing. The coal pillar was in a situation of unloading when the width of coal pillar was five meters. The displacement of the surrounding rock was the least when the width of coal pillar was five meters. Therefore, the reasonable width of protecting coal pillar should be five meters.

1. 引言

2. 计算模型与计算参数

Figure 1. Three-dimensional finite difference grid

Table 1. Moore-Cullen model parameters

3. 计算结果分析

3.1. 煤柱宽度对两帮垂直应力的影响

Table 2. The maximum vertical stress of two gang under different width of coal

(a) 掘进期间 (b) 回采期间

Figure 2. Relation between size of pillar and vertical stress of both sides

3.2. 煤柱宽度对两帮移近量的影响

Table 3. The displacement of two gang under different width of coal

(a) 掘进期间 (b) 回采期间

Figure 3. Relation between size of pillar and both sides’ displacement

3.3. 煤柱宽度对顶板下沉量的影响

Table 4. The subtraction of roof under different width of coal

(a) 掘进期间 (b) 回采期间

Figure 4. Relation between pillar width and displacement of roof

3.4. 煤柱宽度对底鼓的影响

Table 5. The subtraction of roof under different width of coal

(a) 掘进期间 (b) 回采期间

Figure 5. Relation between size of pillar and swelling displacement of bottom

4. 结论

1) 掘进期间和回采期间，实体煤侧的最大垂直应力均受煤柱宽度的影响不大，掘进和回采期间实体煤侧的最大垂直应力分别为17.6~18.4 MPa和22.1~24.2 MPa；煤柱侧的最大垂直应力均随煤柱宽度的增大而增大；煤柱为5 m时，煤柱侧的最大垂直应力为11.2 MPa，低于初始应力(12.5 MPa)，处于卸载状态；

2) 掘进期间和回采期间，巷道两帮移近量、巷道顶板下沉量及巷道底鼓量均在煤柱为5 m时最小。

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