Floor stress evolution laws and its effect on stability of floor roadway

nt er nat i onaI J oum a l ofM i n i n g sci enc e a nd T e chnol ogy23(2013)631—636

C O nt ent s I l st s a va i l abIe at Sci ence

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I nt em a t i onal J oum al of M i ni ng Sci ence and Technol ogy

E I．s】三V I E R j ou r nal hom ep age：w w w．eI s eV i e r．com／I ocat e／i j m s t

Fl oor s t ess evol ut i l aw s and i t s ef ect s t abi l i t of r O aCh|／、，aV

P100r St r eS S e V0l U t l on aW S a nd l S e f f e C t0n St a b¨l V0f f100r r O adW aV

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6s把把K叫L凸60m c0，yB r ee df，l gB∞e，or M f nf昭Di S匹把r P陀ve ncf Dn硼d con的L孙Ⅱndongunfve塔毋0，sc{enc e andnc^no虹∥．Q{H gd∞266590’曲f九a

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R0)M rds：

Fl oo r

M j nj ng a b ut m e n t p淄sufe

Fl O o r r∞dw ay

C r a cks evOl ut i on m ec ha n i s m s A B S T R AC T

A cco r di ng t o t he di s t r i but i o n of abut m ent s t r es s i n a st o pe．t hi s r ese a r ch es t a bl i shed t he m echani cal m odel0f m i n i ng abut m ent pr e ssur e t ra ns m i s si on i n n00r ba s e0n t he t he or v O f se m i．i n6ni t e pl a t e bodV

i n el ast j ci砷．Thj s s t udy t a ke s t he762w or炻ng f ac e0f H ai zj C oa l M i n e as a ca s e j n poi nt．and a na l yz ed t he

dyna m i c e vol ut i on l aw of se amf100r s t r es s du r i n g t he m i ni ng process．W i t h an O r鼬ni c com bi nat i on of t he m i ni ng noo r s t r es s and s ur m un di ng m ck st r ess．t he s t u dy obt a i ned t he chan ge l aw s of t he m axi m um pr i nci pl e s t r es s an d t he m i ni m um on e f or t he noo r r oad w ay s ur m un di nZ m ck w he n m i ni ng t he u口D er w or ki ng f a ce．C ons i de r i ng t he non—c onst a nt pr e ssur e f or ce st at e an d t he cr ack s r e、，0lut ion m echa ni s m s 0f nO or r o adw a y s u r r ou ndi n g m c k，t he r ese a rch bui l t t he m echani cal m odel of r oad w aVst r ess．Si m ul at i o n r es ul t s ver i付t he r el i abi l i t y of t he abave conc l us i ons．M or eover．t hi s m odel c o ul d pm vi de t he t he or et i cal ba si s and t e chni c aI s up por t f or c ont m l l i ng no or m adw ay s uf m u ndi ng m ck．

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C0ns i der i ng t he m a dw a y m ec hani c al m odel af kc t ed by m i ni ng dV nam i c D r ess ur e st ra ddl i ng．t r adi t i ona l l V．i t is com m on t o us e s t r e s s concent r at i on fa c t O r t o r epr es ent t he ef r ec t of m i ni ng abut—m ent口r es s ur e on t he st abi l i t y of noo r m a dw a y11—41．I n addi t i on．t he r oa dw av i s of t en s een as axi svm m et r i c s t res s．～t hough m anv s chol ars ha ve done a l ot of s nl di es o n t he m i ni nZ n00r st r ess di st r i—but i on．h ow t o c O m bi ne t he m i ni ng noo r st r ess and s ur r oundi ng m ck st r ess is s ti II an ur辨nt口r obI em i n cont m l I i ng t he n00r r oad—w ay s ur m undi ng r ock15—8】．Taki ng t he H ai zi M i ne N o．86m i ni ng a re a as a m ec hani c al m O del．t he evO l u t i O n l a w0f noo r st r es s i n762 w or ki ng f．ac e has be en anal yzed i n t hi s s t udy．R e sul t s s ho w t hat t he n00r is i n t he non—c onst a nt pr ess ur e f or ce s t at e．T hus。t he r es ear ch bui l t t he m ec hani c aI m odel of r oa dw aV s t r e ss。a nd anal y zed t he cr acks r ev ol ut i on m ec ha ni s m s0f m a dw a y s ur r oundi ng r ock i n m i ni ng uD D e r w or“nZ fa ce．F i na l l V。t hi s s t udV c ar ri ed ou t t he num er i cal s i m uI at i on t o m ake ve r i6ca t i on．

I n t he N o．86m i ni ng a re a of t he H ai zi C oal M i ne i n H uai be i．C hi—na，t he ent r y of t he r ai l w ay r i se i s l ocat ed i n t he m i ddl e of t he c oal m i ne，w hi ch is des i g ned t o be excaV at ed i n t he noo r of t he9#coa l s eam w i t h an aV er age di s t ance O f20m t o t he9#c oal s e am and 40m t O t he7#c oal sea m．T he m a i n l i t hoI ogy cont ai ns f i ne sa nd一

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E—m蒯口dd麟：hlzhan91122@126．c咖(H．ztlang工st O ne．m udst O ne．A l m udst O ne and pur pl e D l ague m uds t O ne．Fi g．1s how s t he spat i a I r el at i ons hi口bet w een t he r ai l w av r i s e ent r v and t w o c oal s eam s．and t he s ect i on O f m a dw a V i s a s em i ci r cl e ar ch w i t h4m i n net w i dt h and3．5mi n he i ght．1n t he ori鲥nal口l a n。t he anCnor net s pr ay s U D po r t ha S bee n adopt e d and t he an．aVs D aCe be—t w e en bol t s i s800m m×800m m．C0nc r et e t hi cknes s is100m m．T he r ai l w ay r i se ent r v m ay be dest m V ed w hen m i ni ng t he w or ki ng f ac es of uD pe r7#a nd9#coa l s eam s。s o it s houl d be r ei nf or ced i n advanc e19—111．W hen m i ni ng t he w or ki ng f ac es of uD D er7挣and 9#c O aI s eam s．i t is neces s ar y t0know t he ef r ec t0n t he st abi l i t v of nO or m a dw a v i n or der t o s eIe c t a r eas onabl e r ei nf br cem ent f or t he r ai l w aV r i se en t r v．B ased0n t he m ec hani c al m odel0f r ock c om—pl e t e st r es s—st r ai n cun，e。t he m ec hani c al m odel r es ul t ed f r om t he m ck com pl e t e st r es s—st r ai n cu n，e is s egm e nt ed l i ne a rl V i n O r der t o f ac i l i t a t e t he cal cul at i on．N am eI V，i t i s di vi ded i nt o t hree sect i o ns．i ncl u di ng s t r et ch s ec t i on。D l a st i c so f kni n g s ect i on and r es i dual s t r engt h sect i on【11】．C orr es pondi ngl y．t he s ur r oundi ng m ck i s al s o di vi ded i nt o t hree zones．s uch as r es i dual s t r engt h zone．口l a st i c s oft eni ng zon e and el ast i c zone．A ct uany。t he m i ni ng a but m ent pr ess ur e i nevi t abl y l ea ds t o t he change of t he m a xi m um D ri nc i D l e st r es s and m i ni m um pri nc i pl e st r ess concent r at i on f a ct or S丑and 丑2of no or r oa dw ay s ur r oundi ng r ock(see Fig．2)．

3．I．T'r o nsm i ss{o n f aw s i n月oor n6u咖enc pres s ure

旋er t he

ex pl oi t at i on of t he coa l s eam．t he w ei ght of t he st r at a abo V e t he goaf w i l I t ra nsf er and l ead t o a new s uppor t s t r e s s of t he

2095—2686／S—see f|0nt m at t er@2013P u bI i s hed by El s ev i er B．V．on beh al f of C h i na un i V er s i畔of M i ni ng＆Te chnol o斟http：／／dxdoi．org／10．1016／j．Um s t．2叭3．08．002

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l R en】ng

F i吕2．M0de l0f s t r e ss con cent r at i on f actor of m ad w ay s ur m undi ng m c k．

s ur r oundi ng m c k i n t he goa C w hi ch f or m s an abut m e nt D r es sur e zon e as w el I as a di s t ri but i on of abut m e nt pr ess ur e i n f ront of

w or ki ng f a ce，a s s ho w n i n Fi g．3．I t m oves f or w ar d w i t h t he ad—van ce0f w or ki ng f ac e，a nd

f om s a st r ess hei gh t ened a re a and a re—duce d on e i n t he r oo f and f l oor of t he a nt er i or coa l r121．For t he con veni en ce of ca l cul a t i on。F i g．3i s s i m D l i f i ed a s Fig．4．and t he coor di nat e syst e m i s e st abl i s he d．1n suc h coor di nat e s V s—

t em．t he pos i t i on i n w hi ch abut m e nt D r es sur e i ust r es t or es t o ori—

gi nal m ck st r es s i s s el ect ed as gri d or i Zi n。becau s e t he r es ear ch em pha si s her e is t he ef r ec t0f a but m ent pr es sur e0n t he noo r r oa d．

w ay dur i ng m i n i ng．A s s um i ng t ha t．i n t he noor．al l zone s ar e el as—

t i c．exce pt r es i dual s t r en gt h zo ne and pl as t i c s O ft eni ng zone．A f i xe d—poi nt M(x．n)i n el ast i c zon e i s s el e ct e d。he re n i s cons t ant．

T he am pI i f i ed r egi on W near r oa dw av is s ho w n i n F i g．2．P oi nt M is l ocat ed at t he s ur m undi ng m ck el ast i c zone．T hus．m e hori zont al

di s t ance f m m w or ki ng f ac e t o t he poi nt M i s y+S1+s2．T he st r es s evol u t i on pm c ess f or t he poi nt M w oul d be anal V zed dur i ng t he

m i ni ng f r om poi nt D t o poi nt M．

T he abut m e nt pr es sur e i n f ront0f t he w or ki ng f ace m oves a10ng

w i t h w O r ki ng fa ce．F or t he con veni en ce of c al c ul a t i on，gi ven t h at

t he di s t ri but i on and di m e nsi on of w or ki ng fa c e abut m e nt pr es sur e

ar e const ant．and i ts re I at i ve pos i t i on w i t h x a xi s is s ti ll a l so un—

ch anged．So．t h e adv anci ng of w or ki ng f ace i s equal t0a hori zont al

m ovem ent0f a but m ent pr es sur e and x axi s i n t he oy di r e ct i O n．I f

t he m ovem ent di st an ce iS y．t he coor di nat e val ue of D0i nt M w oul d be change d i nt o(x，n—y)u nder t he ne w coordi nat es．A ccor d i ng t o

t he t heo哪of se m i—i n丘ni t e pIa t e body i n el as t i c i t y．t he st r es s a t

poi nt M cau s ed bv abut m e nt pr ess ur e is as f ol I o w i ng1131：

Fi吕3．A but m e nt pr ess ur e di s t r i b ut i on ar ound w of ki ng f ace．1．qo i s t he ver t i cal

r ock s t r es s，and t he va l ue i s yH：2．L2i s t he l engt h w hen m c k s t r e ss i s ze m i n90af．3．

h i s t he l engt h w hen r es idual a b ut m e n t pr ess ur e r et um s t o m c k s t r e ss i n goa t4．S1

i s t he l engt h bet w ee n m i ni ng w or ki ng f ace a nd a b ut m e n t pr es sur e peak：5．s2i s t he

l engch be t、Ⅳeen l ead a b ut m e n t pr es sur e peak a nd pI ace r et um e d t o m c k st r ess．仃x镀

城

2，n

码一元Z，

Fi g．4．D i s t“bu non char t0f a but m ent pr es s ur e

q(毒)x3d善

[x2+(n—y一{)2]2

Subt r act i ng t he m ck s t r e ss口n f而m di s t ri but i on f o r m O f abut—m e n t pr e ssur e(as s ho w n i n Fi g．3)．t he i ncr em ent al por t i on of abut m e nt pr es sur e i s s hO w n i n Fi g．4．de nO t ed as t he t r i angl e^B C and pol ygon^D E F．A cc or di ng t o t he equi l i br i u m condi t i on of f or ce。w he n A B C s a r ea equ al s w i t h A D E F’s ar ea．i t can be exD r e s s ed as f ol l ow s：

q胁≥×q0-(s1+s2)×学q。

W hen pa r am e t er s良an d S1．S≥，￡2

a r e det el l m i ned。each s ect i on of t he a but m ent pr ess ur e ar ound t he w or ki ng f ace．“．L2．￡3．and t he i ni t i aI coor di nat es of S1，s2．s3can be obt ai ned accor di ng t0Eq．(2)．T aki ng t he obs e n，ed st r at a beha vi or c ha ra ct er i s t i cs of t he762 w or ki ng fa c e i n t he7#coa l s ea mO f N o．86m i ni ng a r ea a s an exam—pl e，良=2．5．S1=10m，S2=30m，￡2=10m．a nd t he cor r es p ondi ng coor di nat es of poi n t s B．C D，E F can a l so be obt ai ned accor di ng t o E q．(2)a nd s ubs t i t ut e t hos e re sul t s i n E a．(1)a nd t h en car r v ou t i n t egrat i o n f or t he s ect i on of s3．s2．S1．￡1。￡2t o s ol ve expr e s—si ons【14】．

A ct i on s pher e of abut m e nt pr ess ur e of t he丘rs t s ect i on S≈i s f而m ze m t o i n厅ni哪poi nt【0，o。)．and t he val ue of l oad c ol l e c t i on degr ee q1({)i s qo．A nd s ub s t i t ut i n g t hem i nt o E q．(1)and t hen t he s ol ved re sul t s ca n be expr es s ed as f ol l ow i ng：以，2一委Z。。iij=_渤

旷一行篱挈等㈤¨√o|x2+(100一y一{)21‘、’干

2J r。。qo x2(100一y一{)d考

‘叫12一元．／0i了；i五元Ij研

B as ed o n t he s am e cO m put i ng m e t hod．w e s ubs t i t ut e t he l o ad c oI l e c t i on degr ees of B

C C D，EF，al ong w i t h t he c ol l e c t i on degr ees f}o m poi nt F t o t he negat i V e i n丘ni哆poi nt．，(一∞，0】i n Eq．(3)．and t he n吼，吩a nd T叫r es ul t ed f r o m a but m ent pr es sur e a ct i ng o n c oal s e amf100r s t r a t a a t poi nt M are：

叽=crxl+％+叽3+％+以5

O y=O”+O珏+O y3+o¨+O归

T w=T叫1+f删2+T社3+T州+T科s

T he pri nc i pal s t r e s s of poi nt M coul d be s ol v ed as：

盯1

cr3=

(5)

§

H Zha呜ef dL／m把m a“D加f J0um口f o，M i ni，l gscf en ce ond丁e chnof q斟23偿0”)63l一636

3-2．C^ar l ge f ow s q厂椭e sm，s s concen打0don，nc∞r0，月00r r0口d w ny

s ur r oundf ng r o伙du—r l g m f n机g7带c0Ⅱf se nm

St r es s concent r at i on f act or s丑1(x，y)and五2(x，y)can be obt ai ned

f r om t he pri nc i pal st r es s change I aw．B ecaus e t he ve r t i ca I di s t ance

f r omt he coa l s e am t0poi nt M is c onst ant．t he re fore．st re ss c o nc en—

t ra t i on f ac t or is t he m nc t i on of t he i nd epende nt var i abl e y w hen x

is cons t ant．S i m pli如ing st r ess concent r at i on f ac t ors i s as五1(y)and

五2p)．w hos e expr ess i ons ar e九(y)=鲁and五2(，，)=鲁．A ssum i ng

t he i ni t i al di st an ce f m m t he w or ki ng f ace t o poi nt Mi s140m，

t he veni cal di s t ance f r o m7井coal s ea m t o t he m a dw a V is40m．

t hen t he c00r di nat e val u es O f poi nt M ar e x=40m．n=100m．

w hi ch m e ans t hat t he w or ki ng fa c e w oul d m O ves f or w ar d abo ut

400m．T he change l aw s of pri nc i pal st r es s fa c t or of poi nt M dur i ng

7#c oal s e am m i ni ng ca n be obt ai ned f r om E q．(5)．a s s ho w n i n

Fig．5．

Fm m Fi g．5。i t can be s een t h at t he m a xi m um D r i nci口al s t r e s s of

口0i nt M r eaches t0t he m a X i m umval ue1．28w hen w or ki ng f ace

ad vanc es t0120m。w hi l e t he m i ni m um pr i nci口al st r es s c o nc e n t r a—

t i on f ac t or is0．9．

3．3．E sm6f西，I m en c0，roadwⅡy，0r ce m od ef und er m e non—cons m nc

pTes s uT e forc e st m e

A ccor di ng t o Eq．(5)，shear st r es s w i I l appe ar unde r t he f l oor

dur i ng t he advanc e0f w or l(i ng f ace，and t he m a dw a y is unde r

t he s t a t e0f nO n—c onst a nt口r e s s u r e f or c e．Then．t he m a dw a y f or ce

m O del unde r t he non—c onst a nt D r es sur e f．0r ce s t a t e is c ons t r l l c t ed

115】．A s i s s how ni n Fi g．2。poi st he s uppor t er r e si st ance of r o adw a y

sur f j ce．

3．3．1．E f口s c{c zone s cI‘ess a nd嘲e d印fⅡcem en￡sof V fng

(1)Elas t ic zon e st r ess f unct i on s ol V i ng

A l t hough sn．es s f i s j ust七he m nc t i on of r a di a l coor d i nat e r unde r

st at i c pr e ss．i t a l s O has a r el a t i ons hi p w i t h口bec aus e0f t he ef f ec t

f r om s hear st r ess．s o s t r es s‘i n el ast i c zon e ca n be expr es s ed as：

∞95 90衢∞}：!{封蚓二譬斗封：主土尉划

L—一』—J—l0一一饕上一0上扛I一二一I～一J ；{j j}}N l}，一／：l’1

}一{一十～卜十—一十一’…：一{—卜_P、}．：40斗一卜十一一l f……{

w口抽啦ct耐v州di搴I机ce c砷

(a)M a xi m umpri ncipal s廿℃ss

b)M i ni m um pnnci pal st res s

晦5．M i nm g coe珩cl ent cha nge l aw of m adw ay

633 r=；[(弛一等+：Q产+臼一)cosza+z(zcs+臼剐nr+锄+z臼产一矿]

w he r e c1一c8ar e cons t ant s t o be det e m l i ne d．

E q．(6)s at i sf i es t he com pat i bi l i W equat i on i n pol ar coor di na t e s．and t he r el a t i ons hi p bet w e en st r es s f un ct i on and st r es s com po—

nent s is a s f ol l ow s w hen i gnO r i ng t he bod y f or ce：

I n t he i nt er fa ce0f el ast i c zone，m ck0be ys t he M0h卜C0ul O m b yi e l d cr i t er i on and w hen A2(x，y)<五1(x，y)<3，t he r eI a t i ons hi p be—t w e en t angent i al st r ess and r a di a l s t r e s s i s as fol l ow s【15】．

盯砸+盯r e=2A2qo+qo(^一A2)c os2日(8)

w her e盯陀nnd盯。e a r e t he t angent i aI st r es s and r a di a I st r es s of m c k el ast i c zone．r es pec t i V el y．

A ccor di ng t o bas i c con di t i o ns of t he m odel and E q．(8)，t he r e-sul t s can be obt ai ned a s f bnO w s：

吼怖=型出譬产

盯驰I。Rp=旦蔓里三垄—=_塑{亏三害三业T胁1。唧=o

w he r e f坩e is t he s hear st r es s0f r ock el ast i c zO n e：and仃c t he uni a xi al com pr es s i ve s t rengt h of r ock．

St r e ss bounda珂condi ci ons of sum undi ng r ock i n疗ni t y ha ve be en al r eady know n as：

盯陀Ir=。。=0．5qo【(A1+五2一(五1一五2)cos2刎

盯驰l。。=0．5qo[(五1+五2+(丑一A2)cos2卅(9) T恤I，：。。=0．5qo(A1一A2)si n2日

c1一c80，st res s f U nct i o n expr es s i on can be s ol V ed by Eq．(9)．and a na l yt i c exp r es s i o ns0f each st r es s c O m pone nt i n t he r ock el ast i c zo ne coul d be obt ai ned f t om t he st r es s f hnct i on：

盯m=警(山+如)一q。(A，一如)

降一嘉+(三一譬+莉cos2卜

盯驰=铷“)+铷‘’

T r舱=

”争2a一訇

qo(A1一A2)【(r2+2群)cos2日一《]t an2日

2r4

A m o ng t hem，

忭譬业塑丛篙竽旦塑兰

w he r e R。i s t he r adi us of m ck D l ast i c s oft eni ng zO ne：K a coem ci ent．andK=(1+si n妒)／(1一si n妒)：and妒t her ocki nt er nal f r i cti onangl e．

(2)El as t i c zo ne di s D l acem ent f u nct i o n s ol vi ng

I n t he c a se0f uneq uaI s um oundi ng m ck s七r es ses of m a dw a V and s hear s t r es s．di spl acem ent and st r es s of t he el ast i c r e两on m us t m eet t he f oI l o w i ng r e I at i ons hi p：

等=半咿华％

半+；等：半‰一华盯。㈣，a玑．1锄P巩2+2肛．

刁F十7百一了一—丁¨驰

垮

㈤

静褰嘻

=

=

=

听

嘞％

弼Ⅱ∞

”∞∞坩

哪

旧

㈣

哺

旺如一

H 动n 醒ef aJ ．／Jn 旧加咖ndf 扣um 口j o ，M f n 衲留Sd ence ond 丁ec hnoj q 蹦23f 2013，63T 一636

S ubs t i t ut i ng 仃rP ，仃8P ．and T r 8P

i nco

Eq ．(13)，and

t he r a di a l dis

pl ac em e nt f u nct i O

n O f el ast i c s t r e s s zO ne

can

be 0bt ai ned by us i ng

t he boundar y c ondi t i ons “e l r 一。。=0．％l ，_∞=0

and t he t angent i al

di spl ac em ent ％=0at t he axi s(日=O ，冗／2，兀，3冗／2)：u 。：鲁喜蓦端c 沙：一砂，+砂。，+墨i 坚二警

c ，4，

3．3．2．Pf nsdc

s0-厅e nfng zone Ⅱnd

r 《，s fcfua{s n ．engt ，l

zone

D i s pl ace m ent s and

st r es s

expr ess i ons O f t he pI as t i c s O f t eni ng

zO ne

and t he r es i dual

s t r engt h 0n e ca n be s ol V

ed accor di ng t 0t he m et hod appl i ed f or el ast i c zO ne ，how eV er ．due t 0s pace co n —st ra i nt s ，her e t he re sul t s a r e gi V en 【16】：

u ，p ：砖～．y ．m

w her e “r p is t he r adi us of pl ast i c s oft eni ng zone ：比t he

expan s i on

gradi en t

of

pl ast i c

sof t ℃ni ng

zone ，

i n

gener al

c as e

p ；=(肛，m i 。+Ⅳ幺ax)／2．

V =删

纠(6￡謦。嚣‰)

m “)．(肚脚*2)c0翊+掣≯]

旷[蒜+渺”+品∥一警

妒器(∞1。如一等掣恤

+K 『零+胁一埘黟嵋

+K r 型!盐坐生l ㈣…“y ㈣1‘0

L

(K 一1)(*一嵋)

J 、

L 、

(15)

w her e 盯r p and 仃印a r e t he r a di a l and t ange nt i al st r ess e s of pI as t i c s oft eni ng

zo ne

r espect i V ely ：∥=i ：：车％：盯；the r esi dua l

s t r engt h

of pl ast i c s oft eni ng zone ：and ￡印凡and ￡印％t he t angent i al

st r ai n

at

t he el as t i c pl a st i c j uncti on and t he j uncti on of t he pl ast i c sof t e n —

i ng zon e and r es i dual s t r engt h zone ．r es pec t i V

el y ．w her e 仃仲a nd 盯以ar e t he r a di a l st r es s and t angent i al st r es s of r esi d —

ua l s t rengt h zone ，r es pec t i V el y ．

昂：‰(警+，)赢艨由

w he r e

(18)

(19)

(20)

炉(旷戢一瞥存(州蕃+]

(21)

w he r e uo is t he di s pI ac em ent of m adw ay su —．ace ：R 1t he r adi us of r o ck r es i dual s t r engt h z one ．m ：and 瞄t he expan s i on gr adi ent of r es i dual s t r engt h zone ．

4．E ngi neer i ng

sp r ead shee t

a 眦Iysi s

(1)Par am e t er s det em

l i nat i on A ccor di ng t o t he r e al engi neer i ng geol ogi cal con di t i o ns 0f H ai zi

C o al M i ne ．t he cor r es p ondi ng par am et er s ca n be gi ven as f ol l O w s ：口0=10M Pa ：m adw ay

r adi us 粕=2m

：el a s t i c m odul us of m c k m ass

￡；1G Pa ：p oi s s on r at i o “=O ．25：C oh esi on 吼=25M Pa ：哪=2M

P a ：(D ；兀／6：soft e ni ng m odul us of r ock m ass k=F 皇1．5G Pa ：比=一5：瞄=一2：r oa dw ay

s ur f ace s uppor t i ng f or ce po=0．1M Pa ：an d 口=0．

A nd t hen c al c uI a t i ons w

oul d be c ar ri ed O u t t o s ol ve abo ve f bnnul a s ．(2)R oadw av D l as t i c zo ne

T he r adi us es of pl as t i c s oft eni ng

zon e

and r es i dual s t r en gt h

zo ne

a r e

3．47

and 3．29m r es pect i vel y bas ed o n E qs ．(19)and

(20)．D ur ing m i ni ng t he 7#coa l s eam w

or ki ng fa ce ．t he m a xi m um pri nc i pal st r es s concent r at i on f act or of f l oor m a dw a y s ur r oundi ng

r ocki s 五1=1．28andt he m i ni m um one i s 如=0．9．T hen ．t he r adi us of s ur r oundi ng m ck pl as t i c s of t eni ng zon e and r es i dual s t r en gt h zo ne ca n be cal cul at ed a s 3．82and 3．66m ．w hi c h i ncr eases by 0．35and 0．19m c om pa r ed w

i t h t he non —i nnuence si t uat i on ．(3)Sur r oundi ng m

ck st r es s

C ons i der i ng A 1=屯=1．w hi ch m eans m a dw a y is no t i nf Iu —

enc ed dur i ng m i ni ng 。and t he sn _es s di s t ri but i on of r oa dw ay su 卜

m undi ng r o ck is s ho w

n as Fi g ．6a ．The m axi m um pri nc i pal st r ess concent r at i on

fa c t or

of

f 100r

m a dw a y s ur m undi ng

m ck is

五1=1．28and t he cor r es p ondi ng m

i ni m um on e i s 五2=0．9w i t h m i ni ng 7#coa l s ea m w or ki ng f a ce 。Fi g ．6b s hO

w s t he st r es s dis t r i —but i on of m a dw a y s ur m undi ng m

c k ．A s i I I us t r at e

d i n Fi g ．6，i t ca n b

e know n t h at t he m a xi m um t an —

gent i al s t r e s s at t he

i unct i on of t he pl as t i c s of t eni ng zon e and el as —

t i c zon e i s 18M Pa w hen m a dw a y is no t a fr ec t ed by m i n i ng ：a nd t he m a xi m umval ue r eaches t o 21M P a w i t h m i ni ng 7桦coal s ea m

w or ki nZf ace ．w hi ch is 1．16t i m es t h an t he val ue a t pr i m i t i ve s t at e ．5．N um er i caI

si I I I ul a 廿on 柚a 舾i s

5．I ．M od “es 幻6f i s fl m enC

T he

m odel si z e i s

220m ×200m ×120m

(1engt h ×

w i dt h ×dept h)．The l i t hol ogy and m

ec hani c al par am e t er S of t he

卜r 『_；!_；_两订丌开‘

d(m )

“

(b)舷tedby

7#coa l

se 啪m i Il i ng

Fi 蓦6．St r e s s

di s 喇but i O n of s ur m undi ng m

c k a t di f rer ent s t r e ss st at es ．

+L K

禹雀

＼、／甬一‰了e

盯一

+一

+一b 一，

—●坐一巾二，一K 翠生挫

由

㈣

oi

R 一‰

旦‰％

Ⅸ_叭W

』旷渚0

吼吼=

=

融

呦

M e chan i ca l pa阳m et e巧f or m c k a nd coal．

H．动口，lg e c aL／m ceTl lⅡ哟nⅡlJour naf o，M lni，t g sc f阴c e册d丁ec hnol q纠23口0T3)63T一636

I瓣；黧

l；黼燃

睢i嬲舅麓i

Fi g．7．Pr i nci pal s t r e ss m a p0f t un nel i ng r o a dw a y

I i鬻撼i

爵瓣囊激

t：象：∑戮：

F喀8．州nci pa l s t r e ss of m ad w ay a仃ec t edb y m ini ng．

m O del a r e s ho w n i n T abl e1．T he s ect i on s pe ci fi ca t i on0f r ai l w aV r i se ent呵i s4m×3．5m(w i dt h×hei ght)．suppor t i ng pa t t em is cab l e anchor．T he ki nd of bol t i s hi gh．st r engt h r eb ar w ho s e ar r ay s pac e is800m m×800m m．A nc hor s D e ci fi ca t i on is口15．24m m×5000m m．T he a盯aV s pa ce is2400m m×1600m m w i t h3anch or s i n each s ect i on．There is a hori zont al di s p l acem ent cO n s t r ai nt am und t he boundar v of m odel．and t he m O del bot t om has a疗x ed di s D l acem ent cons t r ai nt．I n c al c ul at i on D r oces s，a ve r t i ca l pr es sur e of9．0M Pa is appl i ed o n t he upper boundar y of t he m ode I．and t he s j de pr es sur e c oe f行c i e nt i s1．0．

5．2．N um e—ca f s f r n ufⅡ亡{on r它s u f f s

R oa dw ay s ur m undi ng m ck s t r e s s di s t r i but i ons w i t h r oa dw aV i ni t i al t unnel i ng and a玎-ect ed by7#coa l s e am w or ki ng fa c e m i ni ng a r e s ho w n i n Fi gs．7and8．

A ccor di ng t o Fi g．7，st r e ss r edi s t ri but es af t e r m a dw a y t unnel i ng and s upp O r t i ng．T he m axi m um pri nc i pal st r ess O f s ur r oundi ng r o ck is15．89M Pa．

A ccor di ng t0Fi g．8．t h e m a xi m um pri nc i pal st r ess of sur m und—i ng r ock r eaches t o19．36M Pa and t he prj nc i pa】st re ss c o nc e n t r a—t i on fa c t or is1．22w hen m a dw a y is a ff e ct ed t em pest uous l y dur i ng m i ni ng．

6．C O ncl usi om

(1)A ccor di ng t o t he di s t ri but i on pat t e m of s t o pe s upp or t

pr ess ur e．by t aki ng t he762w or kf a ce i n t he7#c oal s ea m

0f N o．86m i ni ng a re a i n H ai zi C o al M i ne a s an e xa m pl e，

m ec hani c al equat i ons of st r es s change at s om e f i xed poi nt

i n f l O or ha ve be en bui l t bas ed0n t he t he oⅣof se m i—i nf i ni t e

pl a t e body i n el as t i ci W．B esi des．t hi s s t udy obt ai ned t he

st r ess evO l u t i on l aw s0f t he f i xe d poi nt i n n00r dur i ng0ve r—

l yi ng m i ni ng．

(2)W i t h t he co m bi n at i o n of t he no or abut m e nt pr es sur e and

m a dw a y s ur r oundi ng m ck s t r es s，t he m axi m um pri nc i pal

st r es s concent r at i on f act O r0f noo r r oa dw ay s ur r oundi ng

m ck i s1．28w hj l e t he m j nj m um on e js0．9du r i n g m i ni ng

oV er l yi ng762w or ki ng f ace．

(3)M e chani ca l m odel of r oa dw ay s t r e s s w as es t abl i s h ed und er

t he non—c onst a nt pr ess ur e f or ce s t a t e and t he r adi us val u es

of pl as t i c soReni ng zon e and r es i dual st r enm h zO n e a r e

3．47and3．29m r espect i vel y dur i ng m i ni ng7#c oal s e am

w O r ki ng f ac e．T he se val u es ar e0．35and0．19m．1ar ger t han

t he r ad i us val ues r es pect i v el y．con s i d er i n g t ha t t he r oa dw ay

i s not i nnue nce d by m i ni ng．A n d t he t angent i al st r es s0f

r oa dw ay s ur r oundi ng r ock w i t h w O r ki ng f ace m i ni ng is

1．16t i m es t han t he vaI ue unde r s hut dow n s t at e．

(4)T hr ee—dj m ens j on al num er i caJ m odel of f|oor r oa dw av has

be en bui l t accor di ng t o762w or ki ng f．ac e cond i t i ons．T he

pri nci pal s t r e s s cO ncent r at i on f act or of m a dw a y s ur r oundi ng

m c k i s1．22。w hi ch m e et s t he ore t i c al r esul t s．and t he

m ec hani c al m ode l has be en ve r i厅e d r eI i ab l y。w hi ch coul d

pm vi de t he ore t i c al bas i s dat a f or s ur r ou ndi ng m ck cO nt r01．

T he w o r k w as s uppo r t ed by t he N at i onal N at u r al Sci ence Foun—dat i on of C hi na(N o．51074004)．t he0p e n Pm i e ct of St a t e K e y Lab—or at or y B r eedi ng B as e f or M i ni ng D i sas t er Pr event i on and C ont m l of Shandong U ni ver s时of Sci ence and T e chnol ogy of C hi na(N o．M D P C2012K F06)．t he N at u r al Sci ence Fou ndat i on of A nhui Pr ov—i n ce of C hi na(N o．11040606M102)．and Y ou ng T eacher s Sci ence Fou ndat i on of A nhui U ni ver s i口of Sci ence＆T色chnol q删of C hi na (N o．2012Q N Z l4)．

【1】Li X H．Y ao Q王叶zhang N．w a ng D x．zhe ng xG．D i n g xL N um e r i c al si m ul a t i on of s t abi l i乜，of s ur m undi n g m c k i n hi gh hor i zont al s t r e s s r o a dw a y under ov er h ea d m i ni ng．I M i n Saf E ng2008：25(4)：420—5．

121)(i e w B．shi zF’ch en)0‘Lu s L s tabi li t y anal yses of m adw ay su丌0undi ng r ock

i n du ced by ov er h ea d m i ni n g．J C h i na U ni v M i n T e ch nol2004：33(1)：82—5．13】Z ha ng w，z ha ng D s．C he n J B．W ang X F．X u M T．D et em i ni ng t he opt i m um gat e w a y I ocati on f or ext r em e l y cI os e co al seam s．I C hi na U ni v M i n’r echnol 2012：41(2)：182—8．

f4J ya ng8Z．M a Y．A nal ys i s of I aw of w o f k j ng S con cen cr ace d s cr e ss of shor c r a nge s ea m m i n i ng．S up por t C oaI2006：9(2)：13—6．

【5】Z hu SY。J i ang zQ．Y ao P．xi ao w G．A ppl i cat i on of anal yci c m et ho d i n cal cul at i ng no or s t r e ss of a w ondng fa ce．1M i n Saf Eng2007：24(2)：191—4．

16】Z ha ng H L．w ang L G．Com pu t at i on of m i ni ng i n du ced n00r addi t ionaI s t r e s s a nd

i t s app l i cat i on．J M i n Saf Eng2011：28(2)：288—92．

17】Peng w H。D ong忽．Li S C．Boun dar y i ntegral f o r ITl u I a of semⅢane el ast i c时pr obl em a nd i t s app l j catj on．I C hj na U n i v M j n T e ch nol2005：3刖3)：400—4|【81W a ng m：Fan xG．J ia J Q．H u G z．Y ua n zG．E舱ct S of key s t r a t a0n pm t e ct i on w hen expl oi t i ng a st eep．i ncl I舱under l yi ng a pm t e ct i ng s t rat um．J C h i na U n i v M i n T e ch noI2011：40(1)：23—8．

【9】zeng FVT he I oss of s t abi l i H a nd s uppom ng m et ho d f or t he s o f c a nd dy na m i c t u nnel s．I C hi na C oal S0c2007：32(6)：573—6．

H Z^口ng ec n￡／，n把m砷f onaj Joum al0，M f ni ng Scf encP口九d丁e曲no^嚼，23f2013)63l一636

【101w u H．Fang Q z h a ng z M．G on g z M．z onal di s i nt egr at i on pheno m enon i n enc l osi ng m c k m a s s su r r o und i ng d∞p t u nnel s—m ech ani s m and di s cus s i O n of cha阳ct er i st i c D a r am et er s．M i n Sci T e ch nol2009：19(3)：306—11．

…】L i M Y’w a ngL G．Yi G Q，L uⅥ，H，wu J G．111eo r y a nd pm ct i c eof boI t．gm ut i ngon s oft r ock m ad w ay．B ei j i ng：C hj na C∞l J ndust r y Publ i shi ng H ous e：2001．

f121Q i a n M G．S hi P、Ⅳ．M i ni ng pr es s ur e a nd s t r a t a c ont m I．X uzhou：C hi na U ni ver s时of M i f l i n g and T e ch nol og y Pr es s：2003．

【13l X i e G X．Y an g K．chan g J C．A n aI ys i s o n s i t e m e as ur e m e nt of su pp or t pr ess ur e di s t nbu t i on l awf or s e am of f uU y m e c hani zed l o ngw a Ut o口coal cav i ng m ini ng．

C oal Sci T e ch noI2006：35(4)：483—7．【141X u Z L El as t i c m echa ni cs．B e i j i ng：H i gher E d uC at i on Pr es s：1988．

115l s un J s，Lu w B．A nal”i∞l el as topl as t i c s ol ut i on s t o s upport i ng眦k m as s of ci r cul ar t un neI s under as vm m e t r i c l O ad．R O ck S O i l M ech 2007：28(s upp)：327—32．

『161Zh a ng H L St udy o n s t r e s s t r a nsm i ssi on I a w s of m i ni ng no or a nd i t s i n nue nc e o n st a bi l j砷0f n00r m adw a y．X l j z hou：C hi na U ni ver s i W0f M i ni ng a nd T echnol ogy：2011．