CN103823992A - Dimension analysis-based metal mine goaf overlaying strata caving height prediction method - Google Patents

Abstract

The invention relates to the detection on the goaf overlaying strata caving height under a metal mine room-and-pillar method mining conditions. The prediction method is used for determining the physical relation between the overlaying strata height and the ore body thickness, mining depth, construction stress, goaf size and overlaying strata features by using a dimension homogenous principle of the physical law. The method comprises the following steps of firstly, actually measuring on site or indoor measuring the data of the ore body thickness d, mining depth h, construction stress sigma h, goaf area s, rock unit weight gamma, rock loosening coefficient k and hardness coefficient f; substituting the data measured in the step I into a formula: lgH/d=2.1185-1.2359lg gamma ·d/ sigma h+1.3204lgf-3.0502lgk-0.9582lgh/d+0.0114lgS/d2 to obtain the mine goaf overlaying strata caving prediction height H. The method is strong in practicability, safe (without the operation that a person enters a shaft), compact and economic in the complementation process, and avoids the high hazard of the on-site actual measuring on the goaf overlaying strata caving height.

Description

Metal mine overburden of the goaf based on dimensional analysis is caving Height Prediction method

Technical field

The present invention relates to overburden of the goaf under metal mine room-and-pillar method mining conditions and be caving Height Prediction, be the dimension principle of homogeneity that utilizes physical law, determine that overlying strata are caving height and the Forecasting Methodology of orebody thickness, mining depth, tectonic stress, goaf size and the each physical quantity relation of overlying strata lithology.

Background technology

Overburden of the goaf is caving height, is not only the important parameter of digging up mine under water body, and all plays an important role for the selection of the rock burst control of heavily stressed mine, mining methods and mining sequence; Simultaneously overlying strata are caving height and scope, and taking which kind of supporting measure and supporting construction for mine should provide how many support loads etc. that parameter foundation is provided.Being caving is highly a part for overburden of the goaf destruction height, overlying strata to be caving impulsive force large, destructive strong, time of origin is short, causes catastrophic collapse to staff, production equipment etc.Obtain data that overlying strata are caving height the most directly, effective method is field measurement, but as underground mining, after overburden of the goaf is caving, very likely cause follow-up being caving and the generation of other secondary disasters, it is highly extremely unsafe that personnel are caving to on-the-spot field survey.Therefore, explore a kind of predict overburden of the goaf be caving height method very necessary.

Dimensional analysis is a kind of method of setting up mathematical model in physical field, and it is on the basis of experience and experiment, utilizes the dimension principle of homogeneity of physical law, determines the relation between each physical quantity.Especially in the time of the problem of research new phenomenon or more complicated, the physics link, relation and the process that in reply phenomenon or problem, contain are carried out deep analysis, thereby on mathematics, provide clearer and more definite funtcional relationship as far as possible.Metal mine geologic condition is extremely complicated, the influence factor that underground mining causes overburden of the goaf to destroy is also more, wherein major influence factors have following some: mining methods, orebody thickness, mining depth, tectonic stress, goaf size, overlying strata lithology, lithology structure and fault structure etc., how these factors are caving effect of altitude degree to overlying strata, the quantitative relationship that neither one is clear and definite, therefore utilizing the advantage of dimensional analysis to study that metal mine overlying strata are caving is highly than better suited.

Summary of the invention

The object of the invention is to be caving numerical value highly for metal mine overburden of the goaf and be difficult for the defect of field measurement, and provide a kind of metal mine overburden of the goaf based on dimensional analysis to be caving Height Prediction method.

Technical solution of the present invention: a kind of metal mine overburden of the goaf based on dimensional analysis is caving Height Prediction method, comprises the following steps:

The first step: field measurement or indoor test go out orebody thickness d, mining depth h, tectonic stress σ _h, goaf area s, rock unit weight γ, the loose coefficient k of rock, hardness factor f data;

Second step: by first step the data obtained, substitution formula: $\lg \frac{H}{d}=2.1185-1.2359\lg \frac{\mathrm{\γ}\·d}{{\mathrm{\σ}}_h}+1.3204\mathrm{lgf}-3.0502\mathrm{lgk}-0.9582\lg \frac{h}{d}+0.0114\lg \frac{S}{d^2}$ In, can obtain mine worked-out section overlying strata and be caving pre-computed altitude H; In formula: H-be caving pre-computed altitude, unit: m; D-orebody thickness, unit: m; γ-rock unit weight, unit: MPa; σ _h-tectonic stress, unit: MPa; H-mining depth, unit: m; S-goaf area, unit: m ²; The hardness factor of f-overlying strata; K-rock coefficient of volumetric expansion.

By the analysis to metal mine overburden of the goaf destruction height influence factor, the physical quantity involving with regard to the present invention is below resolved and is illustrated: 1. mining methods, because mining methods are in bad quantification aspect Quantitative study, and this research case of choosing is all taked room-and-pillar method exploitation, the overlying strata that therefore the present invention is directed under room-and-pillar method mining conditions are caving height; 2. orebody thickness (d), orebody thickness has determined the height in goaf to a certain extent, and the height in goaf is higher, and the rubble after being caving needs the goaf volume of filling larger; 3. tectonic stress (σ _h), along with the increase tectonic stress of mining depth (h) is increasing, moreover be also to form overlying strata to produce the concentrated key factor of stress; 4. goaf size (d), goaf scope more easily causes being more greatly caving of overlying strata, goaf scope increases detritus after also causing being caving to be filled with the possibility in goaf just less in addition, and the height that is caving like this district and plastic zone likely continues to grow, expansion; 5. overlying strata lithology, because lithology is conclusive on the impact of overlying strata, therefore rock unit weight (γ) and the rock coefficient of volumetric expansion (k) have been chosen in the present invention as research physical quantity, rock unit weight has embodied the mechanical property quality of rock itself, the loose coefficient table of rock has showed the ability of bashing volume after rock failure, and these two physical quantitys all have a certain impact to being caving district's height; 6. lithology structure, lithology structure is that in overlying strata, heterogeneity rock consists of various combination form, in metal mine on goaf overlying strata body not as the such stratiform in colliery obvious, so lithology structure is difficult for dividing, and uses the hardness factor (f) of overlying strata to explain the overall lithology structure of overlying strata here.

With function representation above-mentioned relation be:

F(γ,f,k,d,h,σ _h,S,H)=0 (1)

In formula: H-be caving highly unit: m; D-orebody thickness, unit: m; γ-rock unit weight, unit: MPa; σ _h-tectonic stress, unit: MPa; H-mining depth, unit: m; S-goaf area, unit: m ²; The hardness factor of f-overlying strata; K-rock coefficient of volumetric expansion.

In above formula, have 8 physical quantitys, their dimensional unit is in Table 1([F], [L] represent respectively the basic dimension of power and length):

Table 1 dimensional unit

Determine dimensional matrix:

$\left[\begin{array}{c}\left[F\right]\\ \left[L\right]\end{array}\right]=\left[\begin{array}{cccccccc}1& 0& 0& 0& 0& 1& 0& 0\\ -3& 0& 0& 1& 1& -2& 2& 1\end{array}\right]---\left(2\right)$

According to dimension harmony principle, determine π number, due to tectonic stress σ _hall can represent by basic dimension with orebody thickness d, secondly these two amounts are known quantities.So choosing tectonic stress and orebody thickness is basic dimension, is write as dimensional matrix form and be:

$\left[\begin{array}{c}\left[F\right]\\ \left[L\right]\end{array}\right]=\left[\begin{array}{cccccccc}1& 0& 1& 0& 0& 0& 0& 0\\ -2& 1& -3& 0& 0& 1& 2& 1\end{array}\right]---\left(3\right)$

In conjunction with matlab software, dimension is analyzed:

$\begin{array}{c}A=\left[\begin{array}{cccccccc}1& 0& 1& 0& 0& 0& 0& 0\\ -2& 1& -3& 0& 0& 1& 2& 1\end{array}\right]\\ >>\mathrm{null}\left(A\right)\end{array}---\left(4\right)$

$\mathrm{ans}=\left[\begin{array}{cccccc}-1& 0& 0& 0& 0& 0\\ 1& 0& 0& -1& -2& -1\\ 1& 0& 0& 0& 0& 0\\ 0& 1& 0& 0& 0& 0\\ 0& 0& 1& 0& 0& 0\\ 0& 0& 0& 1& 0& 0\\ 0& 0& 0& 0& 1& 0\\ 0& 0& 0& 0& 0& 0\end{array}\right]---\left(5\right)$

Can be drawn by formula (5):

$\left[\begin{array}{c}\\ {\mathrm{\π}}_1\\ {\mathrm{\π}}_2\\ {\mathrm{\π}}_3\\ {\mathrm{\π}}_4\\ {\mathrm{\π}}_5\\ {\mathrm{\π}}_6\end{array}\right]=\left[\begin{array}{cccccccc}{\mathrm{\σ}}_h& d& \mathrm{\γ}& f& k& h& S& H\\ -1& 1& 1& 0& 0& 0& 0& 0\\ 0& 0& 0& 1& 0& 0& 0& 0\\ 0& 0& 0& 0& 1& 0& 0& 0\\ 0& -1& 0& 0& 0& 1& 0& 0\\ 0& -2& 0& 0& 0& 0& 1& 0\\ 0& -1& 0& 0& 0& 0& 0& 1\end{array}\right]---\left(6\right)$

Can draw 6 dimensionless π numbers by formula (6), as follows:

${\mathrm{\π}}_1=\frac{\mathrm{\γ}\·d}{{\mathrm{\σ}}_h},{\mathrm{\π}}_2=f,{\mathrm{\π}}_3=k,{\mathrm{\π}}_4=\frac{h}{d},{\mathrm{\π}}_5=\frac{S}{d^2},{\mathrm{\π}}_6=\frac{H}{d}$

Therefore, equation can be write as:

$F(\frac{\mathrm{\γ}\·d}{{\mathrm{\σ}}_h},f,k,\frac{h}{d},\frac{S}{d^2},\frac{H}{d})=0---\left(7\right)$

Above-mentioned is theoretical analysis of the present invention, and some cases that are caving below in conjunction with the metal mine overburden of the goaf of room-and-pillar method exploitation, according to the field measurement parameter in these mines, set up overburden of the goaf under metal mine room-and-pillar method mining conditions and be caving forecast model.Table 2 is statisticss that the metal mine overlying strata of some room-and-pillar methods exploitation are caving height and other each influence factors, and the slanting angle of ore body is substantially between 0～35 °.

Table 2 overlying strata are caving each influence factor statistics of height ^*

^*1. more owing to involving physical parameter, the parameter providing in institute's citing document is mostly not comprehensive, so a lot of parameter is again through searching for, consult relevant report on the net, does not list one by one at this.

2. obtain by searching related data for mine rock unit weight, overlying strata hardness factor, the coefficient of volumetric expansion, if orebody thickness, be caving height and clearly do not provide concrete data, only provide scope, generally get its mean value.

3. tectonic stress is tried to achieve by maximum tectonic stress, and its formula is σ _h=6.7+0.0444h (MPa), h is mining depth.

Above-mentioned each physical quantity is carried out to dimensional analysis and calculating, draw characteristic π value (table 3).

The each characteristic π value of table 3

After each dimensionless is calculated, finally show that metal mine overburden of the goaf is caving Height Prediction model:

$\lg \frac{H}{d}=2.1185-1.2359\lg \frac{\mathrm{\γ}\·d}{{\mathrm{\σ}}_h}+1.3204\mathrm{lgf}-3.0502\mathrm{lgk}-0.9582\lg \frac{h}{d}+0.0114\lg \frac{S}{d^2}---\left(8\right)$

Each physical quantity cotype (1) in formula, wherein coefficient R ²=0.703.

From related coefficient, it is closer with orebody thickness, mining depth, tectonic stress, goaf size, overlying strata lithology and lithology structural dependence that metal mine overburden of the goaf is caving height.Under the condition that records above-mentioned several physical quantitys, can predict the height that under room-and-pillar method mining conditions, overburden of the goaf is caving.

Beneficial effect of the present invention:

(1) can be caving Height Prediction to the metal mine overburden of the goaf of the same type that utilizes room-and-pillar method exploitation, precision of prediction is high.

(2) overlying strata are caving predicting the outcome of height, can be mine and take effective support measure, control overburden of the goaf and move and be caving actual parameter is provided, as while taking consolidated fill technology control overlying mining rock to move, can estimate the minimal support intensity that obturation needs.

(3) predict required known parameters (orebody thickness (d), mining depth (h), tectonic stress (σ _h), goaf size (s), rock unit weight (γ), the rock coefficient of volumetric expansion (k), hardness factor (f)) data, be easy to scene or laboratory experiment records.

(4) practical, implementation process safety (not needing to go down into a mine), succinct, economic, avoids overburden of the goaf to be caving the high risk of height field measurement.

Embodiment

The metal mine overburden of the goaf that the present invention draws is caving the quantitative relationship of pre-computed altitude and orebody thickness, mining depth, tectonic stress, goaf size, overlying strata lithology and lithology structure, in order to check correctness and the practicality of formula (8), enumerate three metal mine examples below, carry out relevant verification experimental verification, and data and the data predicted of the present invention to actual measurement contrast.Concrete mine background and the correlation parameter of each example are as follows:

Example 1:

Jiao Chongjinkuang is positioned at Tongling County, Anhui Province, 55 ° of orebody trends, and tendency east southeast, inclination angle is 10 °～30 °, mineral ore thickness is 5～8m, average out to 6m, the average absolute altitude 160m in earth's surface, ore body roof is take silicite and marble as main, f=14～16.In the time that 05 stope is exploited in-460m stage casing, goaf top plate reaches 6.2m across drop height degree, and goaf area is about 400m ², concrete relevant physical parameter is in table 4.

Example 2:

Rushan Gold Deposit is positioned at Mouping, northern Shandong, this ore deposit mining depth 505m, and orebody thickness is 0.27～7.4m, average thickness is 2.73m.All there are alteration, f=13～15 in ore body roof and floor country rock.In the time that 02 stope is exploited in-385m stage casing, occur that the heavy side of ore body country rock inbreak thickness reaches 5～6m, ore body roof is caving area 10m ², goaf area is 6.4 ten thousand m ², concrete relevant physical parameter is in table 4.

Example 3:

Hongtoushan Copper Mine is positioned at Manchu Autonomous County of Qingyuan of Fushun City of Liaoning Province Failing In Hongtoushan town, and ore body average thickness is between 2.3～3m, and ore and country rock belong to moderately stable, mining depth is apart from earth's surface 770m, heavy stress field effect is more remarkable, and upper lower burrs country rock is gneiss, f=12～14.Because deep rock thrust is larger, the possibility that mining occurrence of large-area is caving is very large.According to this ore deposit, to being caving district's statistics, 11# exploiting field stope area is 618m ², wherein the larger area that is once caving is 50～70m ², concrete relevant physical parameter is in table 4.

Table 4 metal mine overlying strata are caving Height Prediction value and measured value contrast *

( ^*4. in table, Jiao Chongjinkuang is caving height measured value 6.2m and records by HILTI PD40 laser range finder; 5. to be caving be highly 5～6m to Rushan Gold Deposit, and getting its average is 5.5m; 6. to be caving area be 50～70m to Hongtoushan Copper Mine ², getting its average area is 60m ², being caving and calculating its radius by spheroidal is 4.37m)

Known by being caving the model predication value contrast that height measured value and the present invention build in his-and-hers watches 4, the error that is caving Height Prediction value and field measurement value in burnt gold-attempt ore goaf is 5.9%; In Rushan Gold Deposit, being caving the predicted value of height and the error of field measurement value is 13.7%; Hongtoushan Copper Mine 11# stope be caving Height Prediction value and measured value error is 1%; 3 engineering test cases are caving the predicted value of height and measured value average error in 6.8% left and right, can meet completely at mine engineering needs.Therefore, the model that the present invention builds can be used as overburden of the goaf under metal mine room-and-pillar method mining conditions and is caving a kind of Forecasting Methodology highly, can be the choosing of parameter of digging up mine under the water body such as ocean, river foundation is provided, the design and the selection that also can be mining methods and mining sequence provide reference; What is more important can be control overlying mining rock and moves and take which kind of supporting measure and supporting construction should provide how many support loads that parameter foundation is provided.

Claims (1)

1. the metal mine overburden of the goaf based on dimensional analysis is caving a Height Prediction method, it is characterized in that: comprise the following steps:

The first step: field measurement or indoor test go out orebody thickness d, mining depth h, tectonic stress σ _h, goaf area s, rock unit weight γ, the loose coefficient k of rock, hardness factor f data;

Second step: by first step the data obtained, substitution formula: $\lg \frac{H}{d}=2.1185-1.2359\lg \frac{\mathrm{\γ}\·d}{{\mathrm{\σ}}_h}+1.3204\mathrm{lgf}-3.0502\mathrm{lgk}-0.9582\lg \frac{h}{d}+0.0114\lg \frac{S}{d^2}$ In, can obtain mine worked-out section overlying strata and be caving pre-computed altitude H; In formula: H-be caving pre-computed altitude, unit: m; D-orebody thickness, unit: m; γ-rock unit weight, unit: MPa; σ _h-tectonic stress, unit: MPa; H-mining depth, unit: m; S-goaf area, unit: m ²; The hardness factor of f-overlying strata; K-rock coefficient of volumetric expansion.