Characteristics of Stratum Structure and Fracture Evolution in Stratified Mining of Shallow Buried High-Gas-Thick Coal Seam by Similarity Simulation

<table class="table-group" id="tab1"><tr><td><table class="table"><tr><td class="thead-hr" colspan="6"><hr/></td></tr><tr class="thead"><td class="align_center" colspan="6">Similar constant</td></tr><tr class="thead"><td class="align_left">Geometry<br/><svg height="11.927pt" id="M1" style="vertical-align:-3.291101pt" version="1.1" viewbox="-0.0498162 -8.6359 11.7244 11.927" width="11.7244pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M238 675C244 702 241 710 231 710C220 710 155 682 74 673L70 643H101C147 643 151 635 142 594L39 111C18 11 36 -12 55 -12C89 -12 170 38 223 103L207 129C176 98 130 68 118 68C113 68 108 72 114 102L238 675Z"></path></g></svg></td><td class="align_center">Bulk density<br/><svg height="14.1649pt" id="M2" style="vertical-align:-5.529pt" version="1.1" viewbox="-0.0498162 -8.6359 13.9714 14.1649" width="13.9714pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M493 373C493 420 472 451 445 451C421 451 400 435 400 410C400 404 402 400 406 394S417 371 417 350C417 259 317 128 256 55H254C260 126 256 262 238 340C219 424 194 451 163 451C128 451 78 413 24 329L52 302C89 353 106 370 121 370C129 370 137 363 147 336C186 231 196 73 184 -16C152 -88 120 -192 112 -238L130 -257C157 -253 213 -227 231 -213C231 -187 234 -77 240 -23C251 -6 277 30 309 69C424 208 493 299 493 373Z"></path></g></svg></td><td class="align_center">Time<br/><svg height="11.927pt" id="M3" style="vertical-align:-3.291101pt" version="1.1" viewbox="-0.0498162 -8.6359 12.4186 11.927" width="12.4186pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M329 433H203L239 587L230 596L147 534L123 433H57L30 395L34 388H115L61 129C37 16 59 -12 85 -12C147 -12 222 58 260 98L241 125C212 95 160 62 144 62C132 62 127 71 138 126L192 386L305 394L329 433Z"></path></g></svg></td><td class="align_center">Strength <svg height="11.927pt" id="M4" style="vertical-align:-3.291101pt" version="1.1" viewbox="-0.0498162 -8.6359 14.5103 11.927" width="14.5103pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M558 454L532 470C512 451 497 442 465 442C421 442 376 450 318 450C146 450 24 313 24 164C24 46 91 -12 183 -12C317 -12 439 105 439 247C439 306 428 346 382 385L383 389C414 384 450 379 485 379C517 379 539 412 558 454ZM357 273C357 191 313 28 205 28C149 28 111 79 111 160C111 266 175 396 280 396C298 396 328 386 341 357C353 331 357 315 357 273Z"></path></g></svg></td><td class="align_center">Elastic model<br/><svg height="11.8174pt" id="M5" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 14.9396 11.8174" width="14.9396pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M615 650H141L132 618C223 612 227 607 212 526L136 123C122 42 112 38 27 32L18 0H522C539 33 580 135 592 166L558 179C536 139 512 100 486 75C454 48 420 41 345 41C287 41 252 42 237 55C221 68 220 100 231 158L261 316H357C455 316 455 309 455 235H489L529 437H494C468 366 460 360 369 360H269L305 565C315 609 316 611 357 611H450C525 611 535 599 548 578C559 556 561 526 560 482L595 486L615 650Z"></path></g></svg></td><td class="align_center">Poisson’s ratio<br/><svg height="14.1649pt" id="M6" style="vertical-align:-5.529pt" version="1.1" viewbox="-0.0498162 -8.6359 14.4007 14.1649" width="14.4007pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M645 631C614 643 545 666 457 666C215 666 23 519 23 283C23 90 158 -16 337 -16C412 -16 489 2 522 10C543 39 590 127 606 167L580 181C519 89 459 18 348 18C201 18 122 136 122 287C122 464 244 632 435 632C544 632 602 595 608 472L639 475C643 526 645 581 645 631Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,8.619,3.132)"><path d="M546 97L529 123C499 91 459 65 450 65C443 65 439 73 445 106C468 226 496 341 523 451H513L436 424C423 357 412 311 403 276C356 195 245 59 190 59C165 59 158 99 166 135L236 445L227 451L152 428L60 18C43 -58 24 -145 24 -183C24 -237 43 -257 66 -257C96 -257 123 -236 130 -224L129 -216C115 -205 96 -156 96 -102C96 -57 105 -7 113 26H115C127 -1 137 -12 158 -12S198 -5 230 19C284 60 332 117 385 186H387C381 154 378 142 370 107C347 1 367 -12 388 -12C422 -12 492 32 546 97Z"></path></g></svg></td></tr><tr><td class="thead-hr" colspan="6"><hr/></td></tr><tr><td class="align_left">100</td><td class="align_center">1.5</td><td class="align_center">10</td><td class="align_center">150</td><td class="align_center">150</td><td class="align_center">1</td></tr><tr class="table-tr"><td colspan="6"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Similar parameters of the test model.</div>

Geofluids

tab1

Table 1

Table 1: Characteristics of Stratum Structure and Fracture Evolution in Stratified Mining of Shallow Buried High-Gas-Thick Coal Seam by Similarity Simulation 

Table 1 | Characteristics of Stratum Structure and Fracture Evolution in Stratified Mining of Shallow Buried High-Gas-Thick Coal Seam by Similarity Simulation 