CN102182513B - Ground stress coal and gas outburst hazard multi-information coupling prediction method - Google Patents

Abstract

The invention relates to a ground stress coal and gas outburst hazard multi-information coupling prediction method. By testing original rock ground stress, coal mechanical strength and a drilling index value in the extraction process and carrying out coupling prediction of coal and gas outburst hazards on test results, a ground stress coal and gas outburst hazard multi-information coupling prediction model is established, thus, the coal and gas outburst hazard information can be fully acquired, the defect of single-index acquisition information insufficiency can be overcome and the coal and gas outburst hazard prediction accuracy can be improved.

Description

A kind of geostatic stress moulded coal and gas outburst risk multiple information coupling prediction method

Technical field

The present invention relates to a kind of Forecasting Methodology of gas outburst risk, especially a kind of geostatic stress moulded coal and gas outburst risk multiple information coupling prediction method that is applicable to channel of coal mining working surface.

Background technology

Coal and Gas Outburst disaster are to cause the dead group of mine group to hinder one of major casualty, the generation of Accurate Prediction coal and effectively prevention accident of gas outburst risk.And present coal and gas outburst risk Forecasting Methodology are mainly the single index method, as adopting coal powder quantity of bore S value, Desorption Index K ₁Value, Δ h ₂, the drilling gas initial velocity q value etc. of gushing out, or these indexs are summarized as empirical formula predict.Because the coal mining geology complicated condition, these indexs can not reflect coal and gas outburst risk comprehensively, and these indexs do not realize coupling prediction truly.Therefore, can not Accurate Prediction coal and gas outburst risk, low index coal and gas burst accident usually appear, cause huge obstacle to the colliery safety in production.Coal and gas outburst mechanism show that geostatic stress is more remarkable on coal road coal and gas outburst risk impact, a half that reaches the coal body compressive strength limit when geostatic stress then can cause the coal body dilatation and easy destruction, and then may cause coal and Gas Outburst under the effect of gas pressure.Coal powder quantity of bore S value can reflect the Changing Pattern of geostatic stress, can be by the stress of primary rock, coal powder quantity of bore and coal body mechanical property are coupled forecasting coal and gas outburst risk.

Summary of the invention

Technical problem: purpose of the present invention provides a kind of geostatic stress moulded coal and gas outburst risk multiple information coupling prediction method, by protolith geostatic stress, coal body mechanical property, mining influence and coal powder quantity of bore index are coupled, fully supplementary set coal and Gas Outburst dangerous information predict the outcome more accurate.

Technical scheme: geostatic stress moulded coal of the present invention and gas outburst risk multiple information coupling prediction method:

A. test in face of adopt in the tunnel maximum concentrated area stress σ in the square coal body _Max, the critical compressive strength that coal sample is measured coal sample is got at the scene;

B. adopt in the face forward coal body construction length from the tunnel and be no less than the boring of 10m, whenever creep into 1m and measure whole coal powder quantity of bore in this 1m section, record respectively the coal powder quantity of bore S in the 1m section ₁, the coal powder quantity of bore S in the 2m section ₂, the coal powder quantity of bore S in the 3m section ₃..., be designated as maximum coal powder quantity of bore S with obtaining coal powder quantity of bore maximum in each section coal powder quantity of bore _Max

C. according to formula:

Calculate respectively 1m section geostatic stress σ ₁, 2m section geostatic stress σ ₂, 3m section geostatic stress σ ₃,

D. according to the geostatic stress value of the diverse location that obtains, utilize the coupling of coal and gas outburst risk multiple information prediction instrument or manual drawing go out the tunnel adopt in face of geostatic stress distribution curve and critical compressive strength straight line in the square coal body, adopt the distance of face apart from the tunnel be critical drilling depth to distribution curve of stress and critical compressive strength straight line first intersection point of adopting face near the tunnel definitely;

Then when size was once tunneled in the tunnel less than critical drilling depth, predicting the outcome was safety; When size was once tunneled in the tunnel more than or equal to critical drilling depth, predicting the outcome was danger, finished geostatic stress moulded coal and gas outburst risk multiple information coupling prediction.

Beneficial effect: owing to adopting technique scheme, by the drilling cuttings desired value in test protolith geostatic stress, coal body mechanical strength and the exploitation process, with these test results be coupled forecasting coal and gas outburst risk, geostatic stress moulded coal and gas outburst risk multiple information coupling prediction model have been set up, energy is supplementary set coal and gas outburst risk information fully, overcome the infull shortcoming of single index supplementary set information, coal and gas outburst risk forecasting accuracy have been improved, for Safety of Coal Mine Production provides important leverage.Simultaneously the stress of primary rock and coal body mechanical strength parameter are the initial time test, only need to test daily prediction index (such as coal powder quantity of bore etc.) and just can realize that the multiple information coupling predicts in daily forecasting process, and forecasting process is simple and convenient, and accuracy is high.

Description of drawings

Fig. 1 is geostatic stress moulded coal of the present invention and gas outburst risk multiple information coupling prediction method schematic diagram;

Among the figure: 1-adopts face in the tunnel; The 2-coal body; 3-geostatic stress distribution curve; The critical compressive strength straight line of 4-; The critical drilling depth of 5-; 6-boring.

The specific embodiment

As shown in Figure 1, geostatic stress moulded coal of the present invention and gas outburst risk multiple information coupling prediction method at first adopt hydrofracturing method, stress relief method (such as hollow luxuriant body) or other the method test tunnel that can test geostatic stress to adopt face 1 the place ahead coal body 2 interior maximum concentrated area stress σ _MaxSimultaneously in coal body 2, get coal sample, and carry out triaxial test, the critical compressive strength of test coal sample, critical compressive strength is the embodiment of coal body mechanical property; Adopt from the tunnel face 1 forwards coal body 2 interior construction length be not less than the boring 6 of 10m, whenever creep into 1m and measure the whole drilling cuttings values in this 1m section or test the index that other can reflect that geostatic stress changes, record respectively 1m section drilling cuttings value S ₁, 2m section drilling cuttings value S ₂, 3m section drilling cuttings value S ₃..., and to get the coal powder quantity of bore maximum value that records be maximum drilling cuttings value S _MaxAs maximum drilling cuttings value S _MaxRepresent that outburst hazard is arranged when surpassing the threshold of " control coal and Gas Outburst regulation ", when without outburst hazard, carry out following continuation and predict.Owing to coal powder quantity of bore can reflect geostatic stress size: drilling cuttings value everywhere stress increases, and reduces and reduces maximum drilling cuttings value S with geostatic stress _MaxCorresponding maximum geostatic stress σ _MaxAccording to following formula,

$\frac{{\mathrm{\σ}}_1}{S_1}=\frac{{\mathrm{\σ}}_2}{S_2}=\frac{{\mathrm{\σ}}_3}{S_3}==\frac{{\mathrm{\σ}}_4}{S_4}=\·\·\·\·\·\·=\frac{{\mathrm{\σ}}_{\max }}{S_{\max }}$

Calculate respectively the geostatic stress value σ at 1m place ₁, the geostatic stress value σ at 2m place ₂, the geostatic stress value σ at 3m place ₃Survey fragment position place geostatic stress value owing to having recorded each, get one by one correspondence of each point midway of surveying section and geostatic stress value.Geostatic stress value according to the diverse location that obtains, utilize coal and gas outburst risk multiple information coupling prediction instrument or manual drawing tunnel to adopt face 1 the place ahead coal body, 2 interior geostatic stress distribution curves 3 and critical compressive strength straight line 4, first intersection point that face 1 is adopted in geostatic stress distribution curve 3 and critical compressive strength straight line 4 close tunnels is adopted face 1 apart from the tunnel distance is critical drilling depth 5: when size was once tunneled in the tunnel less than critical drilling depth 5, predicting the outcome was safety; When size is once tunneled in the tunnel more than or equal to critical drilling depth 5, predict the outcome and be danger, owing to having considered simultaneously the prediction that is coupled of compressive strength limiting value C, protolith geostatic stress and the coal powder quantity of bore index of coal sample in the forecasting process, also take into account simultaneously the digging impact, realized geostatic stress moulded coal and gas outburst risk multiple information coupling prediction.

Claims (1)

1. a geostatic stress moulded coal and gas outburst risk multiple information coupling prediction method is characterized in that comprising the steps:

A. test maximum concentrated area stress in face (1) the place ahead coal body (2) is adopted in the tunnel

, the critical compressive strength that coal sample is measured coal sample is got at the scene;

B. adopt from the tunnel face (1) forwards in the coal body (2) construction length be no less than the boring (6) of 10 m, whenever creep into 1 m and measure whole coal powder quantity of bore in this 1 m section, record respectively the coal powder quantity of bore in the 1 m section

, the coal powder quantity of bore in the 2 m sections

, the coal powder quantity of bore in the 3 m sections

..., be designated as maximum coal powder quantity of bore with obtaining coal powder quantity of bore maximum in each section coal powder quantity of bore

C. according to formula:

Calculate respectively 1 m section geostatic stress , 2 m section geostatic stress

, 3 m section geostatic stress ,

D. according to the geostatic stress value of the diverse location that obtains, utilize the coupling of coal and gas outburst risk multiple information prediction instrument or manual drawing to go out the tunnel and adopt interior the geostatic stress distribution curve of face (1) the place ahead coal body (2) (3) and critical compressive strength straight line (4), adopt the distance of face (1) apart from the tunnel be critical drilling depth (5) to the close tunnel of distribution curve of stress (3) and critical compressive strength straight line (4) first intersection point of adopting face (1) definitely;

Then when size was once tunneled in the tunnel less than critical drilling depth (5), predicting the outcome was safety; When size was once tunneled in the tunnel more than or equal to critical drilling depth (5), predicting the outcome was danger, finished geostatic stress moulded coal and gas outburst risk multiple information coupling prediction.