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1 NAOSITE: Nagasaki Univesity's Ac Title Autho(s) Citation Computational implementation of a G dynamic gound movement and defoma sequence Cai, Yue; Jiang, Yujing; Liu, Baogu Intenational Jounal of Coal Scien 2016 Issue Date URL Right , The Autho(s). This aticle Ceative Commons Attibution 4.0 In ( use, distibution, and epoduction appopiate cedit to the oiginal the Ceative Commons license, and i This document is downloaded

2 Int J Coal Sci Technol (2016) 3(4): DOI /s Computational implementation of a GIS developed tool fo pediction of dynamic gound movement and defomation due to undegound extaction sequence Yue Cai 1 Yujing Jiang 2,3 Baoguo Liu 1 Ibahim Djamaluddin 4 Received: 4 May 2016 / Revised: 31 Octobe 2016 / Accepted: 2 Decembe 2016 / Published online: 27 Decembe 2016 The Autho(s) This aticle is published with open access at Spingelink.com Abstact In the last centuy, thee has been a significant development in the evaluation of methods to pedict gound movement due to undegound extaction. Some emakable developments in thee-dimensional computational methods have been suppoted in civil engineeing, subsidence engineeing and mining engineeing pactice. Howeve, gound movement poblem due to mining extaction sequence is effectively fou dimensional (4D). A ational pediction is getting moe and moe impotant fo long-tem undegound mining planning. Hence, compute-based analytical methods that ealistically simulate spatially distibuted time-dependent gound movement pocess ae needed fo the eliable long-tem undegound mining planning to minimize the suface envionmental damages. In this eseach, a new computational system is developed to simulate fou-dimensional (4D) gound movement by combining a stochastic medium theoy, Knothe time-delay model and geogaphic infomation system (GIS) technology. All the calculations ae implemented by a computational pogam, in which the components of GIS ae used to fulfill the spatial tempoal analysis model. In this pape a tight coupling stategy based on component object model of GIS technology is used to ovecome the poblems of complex thee-dimensional extaction model and spatial data integation. Moeove, the implementation of computational of the intefaces of the developed tool is descibed. The GIS based developed tool is validated by two study cases. The developed computational tool and models ae achieved within the GIS system so the effective and efficient calculation methodology can be obtained, so the simulation poblems of 4D gound movement due to undegound mining extaction sequence can be solved by implementation of the developed tool in GIS. Keywods Computational model Geogaphical infomation system Component object model Complex mining geomety Gound defomation Suface subsidence List of symbols a Subsidence facto & Yujing Jiang jiang@nagasaki-u.ac.jp School of Civil Engineeing, Beijing Jiaotong Univesity, No. 3, Shangyuan Village, Haidian Diatict, Beijing , China Gaduate School of Engineeing, Nagasaki Univesity, 1-14 Bunkyo-machi, Nagasaki , Japan State Key Laboatoy of Mining Disaste Pevention and Contol Co-Founded by Shandong Povince and the Ministy of Science and Technology, Shandong Univesity of Science and Technology, Qingdao , China Faculty of Engineeing, Hasanuddin Univesity, Jalan Poos Malino KM 6, Bontomaannu, Gowa, South Sulawesi 92171, Indonesia b Hoizontal displacement facto C Subsidence tough function C x Subsidence tough in the x diection C y Subsidence tough in the y diection Cðx 2 Þ Convegence component in the x diection Cðy 2 Þ Convegence component in the y diection c Coefficient da Infinitesimal aea ds Subsidence diffeential dt Time diffeential Efc Eo function exp Exponential

3 380 Y. Cai et al. e n Gound movement influence depending on the extaction aea eðyþ Hoizontal stain in the stike diection e 1;2 ðxþ Hoizontal stain in the dip diection e u Hoizontal stain of a subsidence tough along any diection gðyþ Slope in the stike diection g 1;2 ðxþ Slope in the dip diection g u Slope of a subsidence tough along any diection H Depth H 1 ; H 2 ; H 3 ; H 4 Depth of the panel vetices l Mining panel length along stike m Mining extaction thickness P Suface point P 1 ; P 2 ; P 3 ; P 4 Point at the panel vetices Radius of the cicle of influence S dyn Dynamic, shot-tem vetical displacement o subsidence S e Basic influence function of vetical displacement S end Final, long-tem vetical displacement o subsidence S max Maximum subsidence S p ðx; yþ Subsidence at suface point S p ðx; y; tþ Dynamic subsidence at suface point t Time (yea -1 ) vðyþ Hoizontal displacement in the stike diection v 1;2 ðxþ Hoizontal displacement in the dip diection v u Hoizontal displacement of a subsidence tough along any diection w Mining panel width along dip x 2 Random vaiable in the x diection y 2 Random vaiable in the y diection z t Time-delay facto a Angle of mining dip c d Angle of daw to the dip side c Angle of daw to the ise side os Infinitesimal vetical displacement ol Infinitesimal unit length om Infinitesimal unit thickness ov x Infinitesimal hoizontal displacement in the x diection ov y Infinitesimal hoizontal displacement in the y diection ow Infinitesimal unit width owolom Extaction element qðyþ Cuvatue in the stike diection q 1;2 ðxþ Cuvatue in the dip diection q u Cuvatue of a subsidence tough along any diection / Angle of diection hoizontally 1 Intoduction Undegound extaction of coal mining could lead to seious envionment poblems because of suface movement and subsidence. The damage to envionment could continue fo a long time. A numbe of computational methods have been developed fo simulating gound movement and defomation caused by undegound mining (Baeune 1973; Peng and Chyan 1981; Alejano et al. 1999; Zhao et al. 2004). The most widely used method is subsidence engineeing handbook (SEH) fo pedicting subsidence based on the gaphical solutions (Anon. 1975). The SEH method offes fast and easy calculations whee empiical pedictions ae based on actual measued data. Howeve, this method is only applicable fo simple coal panel s geomety and fo solving two-dimensional (2D) poblem only. The pofile functions method have been successfully applied to pedict subsidence pofiles induced by woking in hoizontal o modeately dipping coal seams (Toano et al. 2003), but this method cannot be accounted fo coal seams with iegula panel. The complex cases can be modeled by analytical methods such as finite element analysis which offes some possibilities fo subsidence pediction by Najja and Zaman (1993), Yang et al. (1993), but these ae invaiably faught with some difficulties. Moeove, influence functions method is consideed as a poweful application fo thee-dimensional (3D) subsidence pediction fo all shapes of extaction panels (Sheoey et al. 2000). Howeve, the use of influence functions is vey time consuming and calibation is difficult. A sensitivity analysis method is poposed fo the GIS-based mapping of the gound subsidence hazad nea abandoned undegound coal mines (Oh et al. 2011). With the development of compute technologies, the computational method is widely accepted. Most eseach has focused on final subsidence at the cente line above mining opeations to simulate and assess the suface stuctual damage without consideing the dynamic extaction pocess. Howeve, the occuence of gound movement and defomation caused by undegound extaction has a elationship with its location and mining sequence obviously. It is defined as a fou dimensional (4D) poblem and each of sub-components has a diffeent effect on stuctues subject to subsidence. It is suggested that the location of mined panels is the most impotant

4 Computational implementation of a GIS developed tool fo pediction of dynamic gound 381 paamete influencing coal mining subsidence (Suh et al. 2016). The influence factos of subsidence wok altenately. Fo example, hoizontal stain is a majo component in cacking, tensile failue of concete dam stuctue, and leakage of wate fom a esevoi when it is unde mined. Since it is common fo a stuctue to be subjected to compession and extension stain in diffeent diections, its esponse is not a simple poblem of pedicting to a paticula numeical value of subsidence. It should be subjected to altenating stages of stain owing to the sequence of extaction, and a spatial tempoal (4 dimension) effect must theefoe be consideed. In a 4D numeical simulation of a mining aea with multiple extaction panels in a complicated mining sequence, it is difficult to obtain the component distibution of gound subsidence with the cuent existing pediction methods. Theefoe, it is not possible to assess stuctual damage accuately. Numeical methods that could simulate the movement consideing spatially and tempoal pocesses ae desiable fo the eliable design of the mining layout in ode to minimize stuctual damage. In consideing the development of the compute-based pediction methodology, it is impotant to pedict 4D gound subsidence components at any point with any shape of excavation so as to cove a wide ange of mining geomety as well as to povide automation, intellection, and visualization in the simulation of subsidence pocess. The ecent development of geogaphical infomation systems (GIS) compises a technology designed to suppot integative modeling, to conduct inteactive spatial analysis and fo undestanding vaious pocesses. In case of a pogessive gound subsidence simulation duing undemining, GIS would be effective and efficient in computing such 4D gound movement and defomation if a pediction system could be popely developed. It also should be addessed that the GIS appoach could esult in an uncetain issue once it elies on just a small amount of infomation (Longoni et al. 2016). In ou pesent eseach, a GIS based computational methodology is developed fo calculating the distibution of gound movement and defomation at abitay suface points (Djamaluddin et al. 2012). The GIS based numeical simulation is validated by two study cases. Fist is the pediction of 21-yea of gound subsidence due to complex undegound mining geomety in Japan. Second is the assessment of dynamic gound movement due to undegound mining sequence in China. The tight coupling model, the component object model (COM) using GIS, is used to develop a GIS based tool fo gound movement pediction system. Theefoe in this pape, fist, the fundamental calculation of gound movement ove time using the Knothe time model and stochastic pediction model is biefly intoduced. Second, a GIS-based pediction methodology fo fou-dimensional analysis is descibed. Thid, two case studies ae given fo the validations the GIS-based computational model. Using GIS COM potocol, a computational implementation of the developed tool is discussed fo pediction of 4D gound subsidence fom undegound mining sequences. Finally, the computational system softwae of the developed tool within GIS is pesented. 2 Analytical pediction theoy and thei models 2.1 Dynamic calculation method fo gound movement In an undegound excavation pogess, the excavated zone geatly influences both the ock mass and the gound suface. Hence, the final gound movement that takes place at a given point depends on time and the ceep chaacteistic of the ock mass undegoes. The final value of the subsidence mainly depends on the size and position of the mining extaction. An analytical method was suggested to descibe the ceep chaacteistic (Knothe 1953). Futhemoe, Knothe assumed that the ate of subsidence of a point is popotional to the diffeence between the possible final subsidence Send of this point, owing to extacting a potion of the instantaneous movement of this point at the time that S dyn is consideed (Fig. 1), which is ds dt ¼ cðs end S dyn Þ ð1þ o s t ¼ð1 exp ct Þ ð2þ whee c is the facto of popotionality, which is elated to the physical and mechanical popeties of the ovebuden ock and soil; s t is the time-delay facto; t is the time. The coefficient c is a paamete to descibe the influence of mining and geological conditions on the movement pocess in time. By using the Knothe (1957) model, the gound subsidence at any point could be calculated when the mining ongoing and it is also possible to obtain the othe time dependent vaiation of movement. The Knothe time model is adopted in this eseach fo the dynamic gound movement pediction, and the key pocess is to detemine the time facto coefficient c. The most significant factos influencing the gound movement wee summaized as followings (Whittake and Reddish 1989): Distance fom the woking face; The thickness of ovebuden; The ate of advance of the woking face; The method of the woking panel; and

5 382 Y. Cai et al. Influence cicle of point P V Woking panel t t 1 S p ( x, y, t) P IV III t 1 t 1 t 2 t 2 t 3 II t 1 t 2 t 3 t 4 I t1 t2 t3 t t 4 5 Fig. 1 Illustation of dynamic subsidence analysis of a suface point P by extaction sequence in elation to the time facto The geological stuctue. This is not an easy poblem fo detemining the above influences and calculating the facto of popotionality. Howeve, with a seies of measued time-subsidence cuves in the gound suface, the coefficient c, descibing the gound movement ate, could be detemined (Bey 1977; Buns 1981). The dynamic gound movement at a time of a given point could be fomulated in factions if its final subsidence accoding to Katzsch (1983). To obtain the coefficient c, the time-movement cuves of the measued data fom in situ investigations of subsidence should be daw at fist. Second, by knowing the final subsidence ate, the pogessive subsidence data, and thei inteval time, the coefficient c can be calculated by backanalysis of Knothe fomulae. Finally, the typical coefficient c in the coesponding mining egions could be deived by analyzing seveal numbes of the measued stations. 2.2 Stochastic medium theoy and spatial subsidence pediction In all pediction methods, the assumption of ock mass behavio geneally epesents continuous o discontinuous mateials. Two concepts have been devised with special egad to the mining subsidence pocess and seem to be adaptable especially to discontinuous mateials. The fist concept is the ock mass as a stochastic medium and second concept is the gap-diffusion as epoted by (Baeune 1973). Because the ovelying stata behave in a complex manne, and the movement of the ock mass is govened by a numbe of known and unknown factos, a stochastic medium theoy is a widely accepted model fo the pediction of 3D gound movement (Litwiniszyn 1957). Based on stochastic medium theoy, a seies of solutions fo subsidence calculations in diffeent geological and extaction conditions have been obtained in China and Japan. The stochastic solutions have been adopted in mining pactice and constuctions of undegound space to solve the excavation poblem unde ailways, ives and buildings. A stochastic medium model is a tool fo estimating pobability distibutions of potential outcomes by allowing fo andom vaiation in one o moe inputs ove time. To calculate movement of a suface point P using the stochastic model, an excavation panel can be divided into infinitesimal aeas. Accoding to the pinciple of integated subsidence effect of the excavation panels, the consequence would be equal to the sum of the effects caused by those infinitesimal aeas. Based on the stochastic medium theoy, the occuence of a ock-mass movement ove the extaction element may be a andom event that takes place with a cetain pobability. A unit with infinitesimal width, length and thickness (owolom) in an extaction panel is called the extaction element. The vetical displacement at any point in the movement slice is defined as the basic influence function (S e ). An event in which suface movements take place in an infinitesimal aea, da ¼ dxdy, at hoizon z, with point Pðx; y; zþ at its cente, is equivalent to the simultaneous occuence of two events composed of a movement in the hoizontal stip dx and the hoizontal stip dy though point P (Fig. 2). Fundamentally, the pobability can be witten sepaately fo these two events by Cðx 2 Þdx and Cðy 2 Þdy, espectively, whee C is the subsidence slice function. The pobability fo a simultaneous occuence of these two events is

6 Computational implementation of a GIS developed tool fo pediction of dynamic gound 383 Fig. 2 Illustation of the pobability pediction of gound movement at a point as a esult of the extaction element within a given extaction panel PðdAÞ ¼Cðx 2 ÞdxCðy 2 Þdy ¼ Cðx 2 ÞCðy 2 ÞdA ð3þ Fo calculating the othe components of gound movement, such as vetical displacement, hoizontal displacement, cuvatue, slope and stain, calculation pocedues wee also used. The vetical displacement o subsidence at point P is given: S p ðx; y; tþ ¼S max ð1 exp ct ÞC x C y ð4þ The slope at point P along diection / is given: g / ¼ gðyþc x cos / þ gðxþc y sin / ð5þ gðyþ ¼ S max exp p y 2 exp p y l!! 2 g 1;2 ðxþ ¼ S max exp p x! 2 exp 1;2 1 ð6þ p x w!! 2 2 The cuvatue at point P along diection / is given: q / ¼ qðyþc x cos 2 / þ qðxþc y sin 2 / þ gðxþgðyþ sin 2/ S max ð7þ ð8þ qðyþ ¼ 2p S max 2 y l exp q 1;2 ðxþ ¼ 2p S max 2 1;2 y exp p y 2 p y l!! 2 ð9þ x exp 1 p x! 2 1!! 2 ð10þ x w 2 exp p x w 2 The hoizontal displacement at point P along diection / is given: v / ¼ vðyþc x cos / þ vðxþc y sin / ð11þ vðyþ ¼bS max exp p y 2 exp vðxþ ¼bS max exp p x! 2 exp 1 2!! p y l ð12þ p x w!! 2 2 ð13þ The hoizontal stain at point P along diection / is given:

7 384 Y. Cai et al. e / ¼ eðyþc x cos 2 / þ eðxþc y sin 2 / sin 2/ðvðxÞgðyÞþvðyÞgðxÞÞ þ eðyþ ¼ 2pb S max y l exp e 1;2 ðxþ ¼ 2pb S max 1;2 2S max ð14þ y exp ð p y 2 p y l!! 2 ð15þ x w 2 exp p x w 2 x exp 1 p x! 2 1!! 2 ð16þ whee S max is the maximum possibility subsidence; e n is subsidence influence, depending on the extaction aea (C x C y );m is the coal-seam thickness; a is the subsidence facto; a is the angle of dip; l is the panel length along stike; w is the panel width along dip; ¼ H= tan c, 1 ¼ H 1 = tan c, 2 ¼ H 2 = tan c d, adius of the cicle of influence; c is the angle of daw to the ise,c d is the angle of daw to the dip; and H is the depth along stike, H 1 is the depth along the bounday of the ise side, H 2 is the depth along the bounday of the dip side. 3 GIS based 4D computational model 3.1 A stategy to integate GIS and models Based on the classic calculation method by Knothe function and Stochastic medium theoy, a new spatial model fo subsidence of undegound mining could be developed based on GIS. GIS povides a wondeful platfom fo dealing with spatial data and gaphical output. Howeve, the geneal pupose of GIS, which povides only a basic tool, cannot be employed to model specific poblems. How to integate the subsidence-pediction modeling to GIS is a question to be solved. It is an infomation-integation poblem, a little like combining one GIS to anothe fo data-tansfe puposes. Fo example, analytical subsidencecalculation points that epesent gound movements fo application to a simulation model can be designed to link to GIS automated diectly. At the same time, a modeling study undetaking in GIS supplies a basis fo simplification of the inteaction between the diffeent uses involved though the establishment of a common data stuctue that can be visualized using the same GIS-based system. Joining the vaiety of data, models, and tools into a obust system of GIS is a eseach topic that is appoached anging fom so called loose integation to tight integation. A stategy based on COM technology coupling with GIS was applied to ovecome the poblems of complex geometic modeling of mining panel and data integation in pesent study. The coupling stategy includes integated data management sevices of GIS, and automated exchange of data becomes possible though a standadized inteface using COM method. COM is a standad, which enhances softwae inteopeability by allowing diffeent GIS components, possibly witten in diffeent pogamming languages, to communicate diectly (Matthew and Michael 2002). The integated model is accomplished within the GIS system to achieve an effective and efficient calculation method. 3.2 Integated pediction model within GIS By integating the effect of all extaction elements in an excavation panel as shown in Fig. 3, all the subsidence components (ds p ) elated to a coesponding suface point (S p ), as illustated in the figue by a 3D view of gid points (calculation points) and a 3D polygon (extaction panel), may be calculated. Fo the extaction panel, with efeence to the vecto-based polygon (Fig. 4), the spatial data of panel geomety, mining sequence, gound movement paametes, and excavation depth can be stoed in the 3D polygon. A featue table is used to elate the subsidence paametes in the panel data set of polygon. In the 3D polygon attibute table, PolygonZM is the shape of 3D polygon attibutes, and ID is the extaction sequence. AngDip is dip inclination of seam panel, UpwadAng is the upwad angle of the panel fom the east, and Thick is the extaction thickness. All of these ae elated to the geometical coodinates. The coesponding paametes of subsidence ae epesented by SubFac (subsidence facto), HoMoFac (hoizontal movement facto), TiFac (time-delayed subsidence facto), UpTan (tangent of daw angle in ise side), and DownTan (tangent of daw angle in dip side). The values of depth vetices ae stoed in each 3D polygon that give spatial geomety in x, y, and z. In othe wods, a 3D polygon has spatial geomety that can be used to identify the main stike diection and dip inclination of each panel. Togethe with a spatial model in GIS, a tiangulated iegula netwok (TIN) model is adopted to identify the stike diection and dip inclination of an excavation panel. Subsidence at the suface points is calculated fom the 3D polygon panels as geometical excavation aeas, and each panel of the polygon is efeenced to the global coodinate system in GIS. It is assumed that the inclination of a 3D polygon has an upwad angle diection (u) with a efeence fom the east. To obtain distibution of suface subsidence fom inclined panels, the global coodinate panel (X, Y) is tansfomed to local coodinate (X 00, Y 00 )in

8 Computational implementation of a GIS developed tool fo pediction of dynamic gound 385 Fig. 3 Pobability distibution of dynamic movement at a gid point as a esult of given 3D polygon extaction panels Vetices panel (Featue Identification (FID) 1) x y z West D view of extaction panel 2 Upwad angle FID 0 3 FID 1 1 FID 2 3D polygon panel attibutes dataset FID Shape ID AngDip Thick SubFac HoMoFac TiFac UpTan DownTan UpwadAng 0 PolygonZM 1 PolygonZM 2 PolygonZM 3 PolygonZM ID = extaction sequence; AngDip = angle of dip; Thick = extaction thickness; SubFac = subsidence facto; FID 3 HoMoFac = hoizontal movement facto; TiFac = time-delayed subsidence facto; East UpTan = tangent of daw angle in ise side; DownTan = tangent of daw angle in dip side; and UpwadAng = upwad angle of the panel fom the east. Fig. 4 Example of 3D polygon panels with elated spatial data geomety and featues table of data set attibutes which the upwad angle diection of each panel is set to be the same as the east diection. The adius of subsidence influence cicle of each panel is assumed to be the downwad and upwad pat of the panel, and the main diection of the adius influence cicle is set to be the same as the upwad angle of the panel. An example of a polygon panel befoe and afte coodinate tansfomation is shown in Fig. 5a. The coodinate tansfom polygon panel vetex (x 00, y 00 ) that gives the depth can be pefomed by simple equations. Let global coodinate X, Y and its tansfom coodinate X 00, Y 00 be deived as follows: h X 00 ¼ X cos u p i h þ Y sin u p i ð17þ h Y 00 ¼ Y cos u p i h X sin u p i ð18þ whee (X, Y) ae fo global coodinates, and (X 00, Y 00 ) ae fo local coodinates. The main diection angle of the upwad panel is set as the subsidence-influence cicle diection. The main diection of the upwad angle (u) and the main dip inclination of the panel (a) could be obtained fom the depth value of the

9 386 Y. Cai et al. Y Y Y 3 Y 2 Y 4 P 2 P 3 Noth Vetex Upwad angle East P 4 Tansfom polygon P P4 W4 W 3 3 Noth Upwad angle East Y 1 P 1 X 2 X 1 3 X X Global coodinate system 4 W 1 W 2 X (a) P 2 V V3 4 P 1 2 V 1 V Local coodinate system X Y W 3 W 4 P 3 Polygon afte tansfom panel vetices P 4 Upwad angle W 1 W 2 O P 2 V2 V3 V 1 V4 P 1 X Suface 1 O X min X3 X 1 X max 2 X H 1 Upwad P 2 3D polygon panel P 3 P 1 P 4 d Downwad Z (b) Fig. 5 a Coodinate tansfomation of a 3D polygon panel. b Obtaining the adius of subsidence influence cicles on the tansfomed panel vetices on a panel in the polygon aea. Refeing to the coodinate tansfom, it is able to get the minimum and maximum values of the panel vetices in the x-coodinate. The dip inclination of the panel is impotant fo the calculation of the subsidence-influence cicle aea of each panel. It should be detemined at the fist step. Refeencing known x-coodinate values afte tansfomation, the adii of the subsidence-influence panel cicles could be calculated by the given depths. Figue 5(b) is an example of a panel afte coodinate tansfomation, and a section plan (X 00, Z) that shows the vetices values of the inclined panel s depth. The adius distances at the upwad ( 1 ) and downwad ( 2 ) pats of the panel ae effected by the inclined dip angle a, and the solution equations could be deived as follows: R upwad ¼ðH i þðx min X i Þ tan aþ= tan c ð19þ R downwad ¼ðH i þðx max X i Þ tan aþ= tan c d ð20þ whee H i is the depth of the panel vetex; X min, X max ae the minimum and maximum values of the x-coodinate of panel vetices fo local coodinates; X i is the x-coodinate of the panel vetex; a dip inclination of the panel; c, c d ae

10 Computational implementation of a GIS developed tool fo pediction of dynamic gound 387 the angles of daw fo the upwad and downwad pats of the panel, espectively. 3.3 Computational method algoithm An flow chat is shown in Fig. 6 to demonstate the algoism of pediction analysis using GIS functions to calculate a suface subsidence. In the computational pocess of gound movement, the panel on the global coodinate system is tansfomed into the local coodinate system at fist. The tansfomation coodinate panel is pefomed to get the adius and angle diection of the main subsidence zone. Then, the pediction of subsidence distibution is caied out in the stochastic-pediction pocedues. Finally, the calculated gound movement esults ae summaized accoding to the woking panel numbe. In ode to pedict the gound movement using the GIS functions, the following data, such as calculation points, extaction panels and subsidence paametes should be pepaed at fist. Meanwhile, the input paametes fo gound movement calculations could be sepaated into two categoies. The fist one is the geneation of suface gid points fo poviding calculation points, including the distance of each gid point in the x and y diections, in which the numbe of points along the gid lines, the numbe of gid lines, point intevals along the gid lines, and the gidline diections need to be established. The second one is enteing the calculation data of gound movement, including the extaction panel sequence ID, seam upwad angle, inclination of dip, subsidence facto, excavation thickness, hoizontal-movement facto, angle of daw and time facto. Since the gound movement is calculated only with the above enteing data, the calculation esults of each panel would be uncetain once the input data ae uncetain. 3.4 Computational pocesses using spatial model The gound movement computation is not limited within the GIS. It also could be pefomed outside the GIS. In this case, the GIS system would be used only as a spatialelated database of gound movement fo stoing, displaying, and updating the inputted data. The main advantage of this appoach, using an existing extenal subsidence-pediction model, is to save time in pogamming the model algoithms into the GIS. A disadvantageofthismethodisthecomplicationcausedbythe convesion of complex geometical data to and fom extenal models. Pediction models calculate the GIS layes (suface elevation, seam elevation, mining excavation map) Data module Point depth laye Polygon panel laye GIS spatial analysis Stage = 1, 2,,n Paametes Paametes (suface points) 3D-polygon panels sequence 3D pediction of dynamic subsidence Dynamic output and simulation Paametes Vetical disp; slope; cuvatue; hoizontal disp.; hoizontal stain Subsidence gidpoints GIS spatial analysis Subsidence intepolation Knothe module Stochastic module Data module Paametes ( ) t Paametes ( c ) Time delay calculation Annotations elated pogess function data Fig. 6 Computational pocesses fo 3D dynamic movement pediction using GIS

11 388 Y. Cai et al. movements of a suface point fo an extaction panel in thee dimensions. Because an individual mine may consists of multiple panels and complex geomety, the use of the 3D pediction model fo obtaining the spatial distibution of subsidence is vey time-consuming without the GIS, as each mining panel has to be calculated sepaately. To ovecome the data convesion poblem of complex geometical, the calculation model of gound movement can be established within the GIS. All modules elated to the GIS spatial-analysis function ae shown in Fig. 7. Evey GIS function is implemented by a GIS component. All of the gound movement-elated paametes such as spatial geomety, suface-point calculation data, and the subsidence paametes could be obtained fom the functions of the GIS data module. The suface subsidence as well as vetical displacement, hoizontal displacement, slope, cuvatue, and hoizontal stain ae calculated with the stochastic pediction module. Finally, the suface subsidence gid-point calculation and its subsidence-pediction kiging intepolation can be obtained by a function of the GIS spatial analysis. Because a GIS component is implemented in the calculation model, the thee-dimension poblem can be computed effectively. 3.5 Computational wokflow A thee-step pocess is applicable in ode to implement a subsidence-pediction model in the GIS envionment. In step 1, it includes deciding on an appopiate woking pojection, establishing spatial extents of the study aea, and assembling vaiously used spatial data fom the study aea so that the spatial component can be ovelapped coectly. This step combines the appopiate subsidence data togethe into a GIS spatial database such as a mining-panel map, a seam laye, a suface-elevation laye, and spatial infomation fom ovebuden stata. Step 2 is to make the spatial geomety of the mining panel, in which the gound movement calculation paametes ae stoed. Usually the mining-panel map is digitized manually, tansfomed fom an image into GIS vecto data. In ode to constuct a geomety epesenting the mining panel to stoe the calculation paametes fo the gound movement computational model, a 3D polygon is adopted and each geomety panel is equied fo the depth of panel vetices (co-odinate in the z diection). The pediction value of subsidence is stoed into 3D polygon once it is aived at coectly, and it is combined with the integation of data in step 3. Fig. 7 Pocesses fo dynamic subsidence pediction

12 0 Computational implementation of a GIS developed tool fo pediction of dynamic gound Application of the GIS computational model 4.1 Subsidence esulting fom 21 yeas of mining beneath a esevoi Accoding to the esults of pevious studies, including a sequential calculations of gound movement and a seies of excavation pocess simulations between 1944 and 1967, the following paametes ae obtained: subsidence facto (a) = 0.85, hoizontal movement facto (b) = 0.21, tangent of daw angle (c) = 1.428, The time-delayed subsidence is epesented by the time facto. It shows that the final value completed in 3 yeas (fist yea = 0.83, second yea = 0.90, thid yea = 1). The subsidence continued even afte coal mining was completed, and the maximum value was 3.27 m up to The pogessive subsidence simulation esults of past mining stages including 1950, 1961 and 1967, ae shown in Fig. 8a c. Fo these spatial simulations, all calculation points wee intepolated by using the kiging intepolation method. The simulated maximum vetical displacement is 1364 mm in 1944, and becomes to 1994 mm afte 6 yeas of mining (in 1950). The magnitude is 2505, 2576 and 3012 at 1955, 1958 and 1961, espectively. At the same time, the zeo subsidence contous ae indicated by the dotted line. This line encloses the subsidence aea and identifies the beginning of subsidence and the limit of gound movements that may cause damage to suface stuctues. It is found that a suface subsidence inceased pogessively about fom 1956 to 1967 at the esevoi aea. Eight suveys wee caied out duing the twenty one yea mining peiod to monito subsidence data aound the esevoi evey yea. Subsidence, mm -3, ,015-3, ,764-2, ,512-2, ,261-2, ,010-2, ,759-1, ,507-1, ,256-1, ,005-1, N W E S ,000 M Legend Measued points Zeo subsidence Concete dams Wate Coal extaction panels (a) Fig. 8 a Simulation of subsidence distibution fo mining up to b Simulation of subsidence distibution fo mining up to c Simulation of subsidence distibution fo mining up to 1967

13 0 390 Y. Cai et al. Subsidence, mm -3, ,015-3, ,764-2, ,512-2, ,261-2, ,010-2, ,759-1, ,507-1, ,256-1, ,005-1, N W E S ,000 M Legend Measued points Zeo subsidence Concete dams Wate Coal extaction panels (b) Fig. 8 continued 4.2 Subsidence fom a coal-mining sequence beneath ailway and oad lines A coal mine in China has been studied. Fom Septembe 20, 1999, to July 20, 2000, the longwall face of no is excavated. The aveage mining depth is 269 m below the gound suface. The ovebuden consists mainly of clay, sand, and sandstone of vaying thicknesses. The suface topogaphy of the coal field aea is almost flat. The coal seam thickness is 5.6 m. The aveage angle of dip of the coal seam is 4, and the aveage mining ate of the longwall face is 120 m/month. The stike and dip length of the woking face ae 1160 m and 150 m, espectively. The monitoing points wee aanged along a ailway line and a small oad line with a total of 60 measuement positions. The layout of coal panel and the measuement points is illustated in Fig. 9. The time facto of the subsidence can be calculated by the Knothe time model. The calculation of the time coefficient (c) is 13 yea -1, which is detemined fom the measued points. The time factos fo the elevant duation of influence of the coal panels ae: Fist month: 1 e = Second month: 1 e = Thid month: 1 e = The geneal subsidence paametes could be detemined by the obsevations and boehole data. As a esult, subsidence facto is 0.8, the hoizontal displacement facto 0.2, and the tangents of both the daw angle at dip side ae 2.6 and of the angle at ise side is 2.2. The pogessive suface subsidence owing to the mining sequence can be pedicted in tems of monthly sequences. Figue 10a c illustate the compaison of measued and calculated subsidence point

14 Computational implementation of a GIS developed tool fo pediction of dynamic gound 391 Subsidence, mm -3, ,015-3, ,764-2, ,512-2, ,261-2, ,010-2, ,759-1, ,507-1, ,256-1, ,005-1, N W E S ,000 M Legend Measued points Zeo subsidence Concete dams Wate Coal extaction panels (c) Fig. 8 continued Fig. 9 Plan layouts of measuing points and mining extaction pogess

15 392 Y. Cai et al. Fig. 10 a Compaison of measued and pedicted subsidence cuves with mining pogess in Januay. b Compaison of measued and pedicted subsidence cuves with mining pogess in Febuay. c Compaison of measued and pedicted subsidence cuves with mining pogess in Mach values at the oad line in the months of Januay, Febuay, and Mach, espectively. 5 Computational implementation of the system 5.1 Stuctue of the integated system An integated system based on GIS platfom has been developed to pedict subsidence due to undegound mining in which all calculations and data pocessing have been implemented in a compute pogam as an extension tool in AcGIS, called as mining subsidence damage assessment system (MSDAS-GIS). Figue 11 illustates the whole system stuctue in which a GIS component is used to fulfill the analysis of spatial tempoal. All the subsidence and envionmental impact analysis elated GIS data can be managed and analyzed effectively as the same as the odinay GIS softwae. Spatial analyst and 3D analyst ae used to analyze 3D-polygon panel geomety and to povide moe accuate possibility of input paametes. All data fo the subsidence calculations ae in GIS vecto data, and the final calculation esults can be tansfomed into GIS aste data. At the same time, the composite algoithms and iteation pocedues of the dynamic subsidence analysis poblem can also be implemented pefectly.

16 Computational implementation of a GIS developed tool fo pediction of dynamic gound 393 Fig. 10 continued Fig. 11 The main system of MSDAS-GIS toolba in GIS platfom based on AcGIS of AcMap technology In this eseach a tight coupling method based on COM technology has been used to ovecome the poblems of GIS-based model integation. Figue 12 illustates the coupling models of GIS in which a COM method is used to communicate between the models and the GIS components. The subsidence analysis elated GIS data can be managed and analyzed effectively in the same manne as odinay GIS softwae. In ode to achieve a moe accuate

17 394 Y. Cai et al. Use inteface Seve GIS-AcMap.exe COM potocol Client MSDAS-GIS.dll Fig. 12 Illustation of object inside a GIS AcMap is accessed by COM method possibility of input paametes, the tools of 3D analyst and spatial analyst ae used to analyze the spatial geomety of mining panel. With the poposed method, the composite algoithms and iteation pocedues of the dynamic subsidence analysis poblem can also be implemented successfully. The concept of a GIS-based component model is that developed system can be assembled with eusable model components. Dynamic models of impact assessment and pediction systems often have common components that usually epesent a specific aspect o functionality of the system. GIS softwae is built based on common modula of shaed components. These components ae intechangeable which can be eplaced by simila components depending on how the use wants to customize the model. Afte some specified ecoding o modification, the elated functional pats can be built with standad intefaces and become eusable. These eusable components fom a esouce that is available fo ceating customized simulation models. Diffeent components may come fom a same paent model and diffeent models may povide simila components, which have diffeent intenal stuctues and calculations but pefom the same functionality. In the system of MSDAS-GIS, the component model is employed fo fulfilling all the GIS functions. 5.2 Computational pocess and system inteface In this pat, the whole computational pocesses of mining subsidence analysis ae expessed in moe detail. The subsidence data modeling is established as an integal pat of the GIS, and the developed system povides a way fo subsidence pediction as well as envionmental impact assessment analysis. Figue 12 shows the main inteface of MSDAS-GIS toolba within GIS. It could be divided into thee categoies that have elationship with the implementation calculation pocess of mining subsidence. The system povides a set of suppoting tools that is using the complex data pepaation while enabling the utilization of the spatial and 3D analyst suppoted by GIS. In ode to pefom a subsidence pediction analysis in GIS, thee ae fou steps named as geneal setting, pepocessing, subsidence calculation and post-pocessing. The inteface of the pe-pocessing of subsidence calculation is given in Fig. 13a. This fom is used to pepae a 3D GIS-polygon dataset in which all the subsidence paametes and geometical paametes and extaction sequence infomation ae included. MSDAS-GIS povides tools fo ceating a new dataset of 3D GIS-polygon, identifying its polygon depth as well as panel vetices numbe. Thee ae five steps in subsidence paametes pepaation that is necessay to pefom the paamete-elated 3D GIS-polygon. In ode to calculate subsidence of a gid point, a pogam was developed to geneate suface gid points fo poviding calculation points, including the distance of each gid point in x and y diections, whee the numbe of point along gid line, numbe gid line, point inteval along gid line, and gid line diection ae needed to be established. The fom inteface fo geneating a gid point is shown in Fig. 13b. Figue 13c shows the fom inteface fo calculating suface subsidence due mining sequence. Due to panel sequence elated subsidence data and multiple calculation panel, it is difficult to manage all of these data without 3D-polygon-based datasets, thus in the calculation system, a polygon dataset is used to stoe all panel datasets as a spatial geomety. In this 3D-polygon panel dataset, a featue table is used to elate the subsidence paametes and spatial geomety. Developed system povides fom inteface in the calculation to make an easy calculation phase pocess and calculation of 3D subsidence components in abitay diection. The fom inteface fo post-pocessing subsidence pediction is given in Fig. 13d. All the calculation esults can be stoed into GIS point-gid. Each calculation point such as vetical displacement, slope, cuvatue, hoizontal displacement and hoizontal stain can be tansfomed into a GIS aste by a suface intepolation as well. Simulation gound movements fo each calculation numbe ae possibly shown in this inteface. In subsidence calculation pofiles, the calculated components and phase numbes of woking panels will be shown on MapView on the main inteface, as shown in Fig. 14, and the gound movement s components changing will be shown by two dimensional (2D)-gaph. 6 Conclusions This pape has demonstated a GIS based developed tool to pedict 4D subsidence fom undegound mining sequence. The stategy of close coupling between a pediction model and GIS using COM technology is used. Using a GIS-based pediction methodology, it is possible to calculate spatial

18 Computational implementation of a GIS developed tool fo pediction of dynamic gound 395 Fig. 13 a The fom inteface fo Pe-pocessing subsidence pediction. b The fom inteface fo Geneating gid calculation point. c Fom inteface fo Calculation coe subsidence pediction based on stochastic method. d The fom inteface fo Post-pocessing subsidence pediction

19 396 Y. Cai et al. Fig. 13 continued and tempoal gound-suface movements induced by multiseam longwall mining. Diffeential-subsidence chaacteistics, such as pogessive vetical displacement, slope, cuvatue, hoizontal displacement, and hoizontal stain, can be computed using the GIS developed tool. Subsidence in the study aea of Japan is simulated. The calculated esult has been used to evaluate subsidence-induced damage esulting fom mining beneath a esevoi. The pogessive gound subsidence esulting fom undegound mining sequence in the study aea of China is also

20 Computational implementation of a GIS developed tool fo pediction of dynamic gound 397 Fig. 14 An example of the calculating pocess fo dynamic movements showing the simulation of five components subsidence movements along the centeline of longwall mining simulated. The calculated esults have been used to compae obseved subsidence values at oad and ailway lines. It should be addessed that the GIS elated analysis esult has an uncetain issue because it elies on a small amount of infomation. The accuacy of the simulation esults depends on the oiginal GIS data. As the futue study, the GIS-based developed tool should be impoved to conside the effect of steeply mining, heteogeneity of ock mass, and influence of fault and suface topogaphy conditions. Moeove, a multilaye appoach should be pefomed to detemine divese factos such as geological stuctue and gound wate level, which can impove the GIS subsidence pediction model. Open Access This aticle is distibuted unde the tems of the Ceative Commons Attibution 4.0 Intenational License ( tivecommons.og/licenses/by/4.0/), which pemits unesticted use, distibution, and epoduction in any medium, povided you give appopiate cedit to the oiginal autho(s) and the souce, povide a link to the Ceative Commons license, and indicate if changes wee made. Refeences Alejano LR, Ramiez-Oyanguen P, Taboada J (1999) FDM pedictive methodology fo subsidence due to flat and inclined seam mining. J Rock Mech Min Sci 36(4): Anon (1975) Subsidence enginees handbook. National Coal Boad, London Bey DS (1977) Pogess in the analysis of gound movements due to mining. In: Geddes JD (ed) Poceedings of the lage gound movements and stuctues, cadiff. Pentech Pess, London, pp Baeune G (1973) Subsidence due to undegound mining. Gound movements and mining damage, US.IC 8572 Buns K (1981) Pediction of delayed subsidence. In: Poceedings of the suface subsidence due to undegound mining, Mogantown, West Viginia, pp Djamaluddin I, Mitani Y, Ikemi H (2012) GIS-based computational method fo simulating the components of 3D Dynamic gound subsidence duing the pocess of undemining. Int J Geomech ASCE 12(1):43 53 Knothe S (1953) Rate advance and gound defomation. Begakademie 5(12): Knothe S (1957) Obsevations of suface movements unde influence of mining and thei theoetical intepetation. In: Poceedings of the Euopean congess on gound movement, pp Katzsch H (1983) Mining subsidence engineeing. Spinge, Belin Litwiniszyn J (1957) The theoies and model eseach of movements of gound masses. In: Poceedings of the Euopean congess on gound movement, pp Longoni L, Papini M, Bambilla D, Aosio D, Zanzi L (2016) The isk of collapse in abandoned mine sites: the issue of data uncetainty. Open Geosci 8(1): Matthew JU, Michael FG (2002) Integating spatial data analysis and GIS: a new implementation using the component object model (COM). Int J Geog Inf Sci 16(1):41 53 Najja Y, Zaman M (1993) Numeical modeling of gound subsidence due to mining. Int J Rock Mech Min Sci Geomech 30(7):

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