采礦工程專(zhuān)業(yè)--外文翻譯(已修改)
2024-12-22 00:45 本頁(yè)面
【正文】 英文原文： Analytical model and application of stress distribution on mining coal floor Abstract： Given the analysis of underground pressure， a stress calculation model of cola floor stress has been established based on a theory of elasticity． The model presents the law of stress distribution on the relatively fixed position of the mining coal floor： the extent of stress variation in a fixed floor position decreases gradually along with depth． The decreasing rate of the vertical stress is clearly larger than that of the horizontal stress at a specific depth． The direction of the maximum principal stress changes gradually from a vertical direction to a horizontal direction with the advance of the working face． The deformation and permeability of the rock mass of the coal floor are obtained by contrasting the difference of the principal stress established from theoretical calculations with curves of stressstrain and permeabilitystrain from tests． Which is an important mechanical basis for preventing water inrush from confined aquifers． Key words： model； coal floor； stress distribution； analysis 1 Introduction With the development of coal seam mining， The stress field of rock strata of coal seam floors will change and continue to be redistributed because of the effect of mi ning． The results will bring on floor deformation， displacement and possible destruction to attain a new balance[1]． A study of the law of stress distribution of floors has important， practical implications in understanding deformation and destructive characteristics and predicting water inrush from floors and for designing suitable locations for tunnels and selecting maintenance methods when depth increased． At present， the study of the law of stress distribution of floors mostly proceeds from a number of calculations based on finite element analyses and similar material tests[26]． In this paper， the study of stress distribution of floors in relatively fixed positions is discussed analytically with a theory of elasticity and we present an application bined with actual data of a particular site． 2 Fundamental principle The formulas of stress distribution are derived from the superposition principle，given the theory of elasticity on distributed loads on a semiinfinite plane[78]． The vertical distribution load of AB on a semiinfinite plane is assumed to be q(x)， as illustrated in . We want to solve the state of stress at a specific point inside a semiinfinite plane，such as point M ． Supposing the coordinate of point is (x， z)， the micro1ength dζ from the origin of coordinate is ζ on the AB segment， the microconcentration force dp=qdζ is regarded as its force and the state of stress of the microconcentration force at point is defined as follows． In order to calculate the stress at point M from all distributed loads， the stress which is caused by every microconcentration force is superposed． We need to integrate Eq.(1) from ζ= a to ζ= b and Eq.(1) then bees： 3 Stress calculation of coal seam floor of the mechanical model Based on the theory of underground pressure， the mechanical model of supporting pressure in front of the working face can be simplified， as shown in [911]． Where the OA segment is the plastic area， with a length of x0； the AB segment is the elastic area， with a length of L0 x0． In order to calculate easily the supporting pressure of both areas pz(1) ， pz(2)， without losing its rational， we can assume the following two linear functions： Where is the supporting pressure of the plastic area(kPa)， the supporting pressure of the elastic area(kPa)， the maximum stress concentration coefficient，the width of the plastic area(m)， H the buried depth of the coal floor(m)， the width of the area affected by the supporting pressu
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