Monitoring and forewarning method for coal-rock dynamic disasters based on electromagnetic radiation and earth sound

A monitoring and forewarning method for coal-rock dynamic disasters based on an electromagnetic radiation and an earth sound, wherein an electromagnetic radiation sensor and an earth-sound sensor are respectively arranged on a coal body or a rock body for collecting an energy and a pulse number of the electromagnetic radiation, and an energy and a frequency of an earth-sound signal in real time as original data;

• the method comprises the following steps:
• step (1), calculating P(t), wherein the P(t) is a weighted average value of a research parameter in a time period, and the P(t) is calculated according to monitoring data collected by an electromagnetic radiation and an earth-sound monitoring system;
• step (2), calculating D(t), wherein the D(t) is a deviation value of the P(t);
• step (3), calculating |D(t)|, wherein the |D(t)| is an average value of the |D(t)|, and the |D(t)| is an absolute value of the D(t) during a period of normal mining of a working surface, and using the |D(t)| as a deviation threshold value;
• step (4), calculating DS, wherein the DS is a number of times that the deviation value D(t) is greater than the deviation threshold value |D(t)| in one day;
• step (5), normalizing the DS to obtain a monitoring and forewarning index ε;
• step (6), forewarning a hazard state of a dynamic disaster of the working surface in real time according to the ε and a forewarning method, and determining a hazard level of the dynamic disaster,
• wherein, in the step (1), the research parameter is one or more of an electromagnetic radiation energy, an electromagnetic radiation pulse number, an earth-sound energy, or an earth-sound frequency, and the weighted average value of the research parameter P(t) is a result of a cumulative sum of the research parameter divided by a time window length during the time period,
• the monitoring and forewarning index ε in the step (5) is calculated by the following formula:
• ɛ
• =
• D
• S
• -
• D
• S
• ⁢
• -
• ⁢
• min
• D
• S
• ⁢
• -
• ⁢
• max
• -
• D
• S
• ⁢
• -
• ⁢
• min
• ,
• wherein DS-max is a maximum value of the DS during the time period, and DS-min is a minimum value of the DS during the time period, and
• the hazard level in the step (6) includes no hazard, a low hazard, a medium hazard and a high hazard;
• and the hazard level is determined as follows:
• when ε<0.5, no hazard exists, when 0.5≤ε<0.65, the low hazard exists, when 0.65≤ε<0.8, the medium hazard exists, and when 0.8≤ε, the high hazard exists.