【摘要】：隨著地下工程開采深度的不斷增加,在高地應力、高地溫、高滲透壓和爆破開挖擾動等特殊工程環(huán)境下,深部地下工程巖體產生了諸如分區(qū)破裂現象、圍巖大變形、巖爆等新的工程地質災害現象。針對高軸地應力深部巖體分區(qū)破裂現象,采用理論分析、三維相似物理模型試驗、顆粒流數值模擬和現場監(jiān)測相結合的方法,研究了爆炸荷載對高軸地應力條件下深部巖體分區(qū)破裂的影響機理與深部圍巖的變形破壞規(guī)律�；贖oek-Brown準則,理論分析了深部圓形洞室在高軸地應力和靜水壓力條件下圍巖的彈性應力場,推導了洞周圍巖爆破損傷效應的破裂區(qū)分布區(qū)域,得出爆炸荷載對深部圍巖破裂區(qū)寬度的影響范圍。采用“先加載、后開洞、再超載”的試驗方法,開展了人工鑿挖、預埋件抽出和爆破開挖3種開挖方式的深部巖體分區(qū)破裂三維相似物理模型試驗。試驗表明,模型洞室開挖完畢,3種開挖方式的模型洞周應力和應變隨距洞壁距離的增加均呈現出波峰與波谷間隔分布的非線性變化,驗證了分區(qū)破裂是高軸地應力條件下的一種特殊破壞模式。軸向超載過程中,洞周圍巖開始出現環(huán)狀破裂,在環(huán)狀破裂區(qū)內應變迅速增大,在環(huán)狀破裂區(qū)附近應變迅速減小。超載完畢,洞周應變呈現出波峰與波谷的間隔分布,分別對應于圍巖破裂區(qū)與非破裂區(qū)；洞周徑向應力也表現出相似的變化趨勢。模型洞室拱頂和幫部荷載的增加會限制模型洞周的破裂區(qū)范圍。爆炸荷載在洞壁附近圍巖體內產生大量的微裂紋,造成圍巖體力學性能的劣化和完整性降低；在高軸地應力條件下,微裂紋擴展、貫通,形成宏觀破裂區(qū),使洞壁圍巖體的破壞加劇,圍巖破裂區(qū)的范圍擴大；后一層破裂區(qū)半徑約為前一層破裂區(qū)半徑的1.28倍。建立了深部巖體爆破開挖三維顆粒計算模型,對節(jié)理傾角不同的深部巖體進行數值分析,揭示了爆炸荷載作用時間和層狀節(jié)理面傾角對深部地下工程巖體分區(qū)破裂的影響。隨著層狀節(jié)理面傾角的增大,爆破開挖完畢顆粒模型洞周圍巖破裂區(qū)范圍、張拉和剪切裂紋數與應變能增量均呈現出先增大后減小的變化趨勢；當層狀節(jié)理傾角為600時,圍巖體破裂區(qū)范圍最大。開展了錨固支護深部巖體在高軸地應力狀態(tài)下爆破開挖相似模型試驗,發(fā)現錨桿和錨索聯合支護部位未出現分區(qū)破裂,而未支護部位出現了分區(qū)破裂,分析得出錨桿和錨索的聯合作用可實現圍巖應力的轉移和重分布,揭示了錨固支護對深部巖體分區(qū)破裂的抑制機理。現場爆破損傷監(jiān)測表明,采用鉆爆法施工的巷道,左幫爆破損傷區(qū)在6m范圍內,右?guī)捅茡p傷區(qū)在7m范圍內,且3m范圍內圍巖體的損傷程度較大。
[Abstract]:With the increasing mining depth of underground engineering, in the special engineering environment such as high ground stress, high ground temperature, high permeability pressure and disturbance of blasting excavation, the deep underground engineering rock mass has produced such phenomena as zonal fracture and large deformation of surrounding rock. Rock burst and other new engineering geological disasters. In view of the phenomenon of zone fracture of deep rock mass with high axial geostress, the method of combining theoretical analysis, three-dimensional physical model test, numerical simulation of particle flow and field monitoring is used. The influence mechanism of explosive load on the zonal fracture of deep rock mass under high axial stress and the deformation and failure law of deep rock mass are studied. Based on Hoek-Brown criterion, the elastic stress field of surrounding rock in deep circular cavern under high axial geostress and hydrostatic pressure is theoretically analyzed. The influence range of explosion load on the width of fracture zone of deep surrounding rock is obtained. By using the test method of "loading first, then opening holes and then overloading", the three-dimensional similar physical model tests of deep rock mass subzone fracture are carried out, which are excavated by artificial chisel, pre-buried parts extraction and blasting excavation. The experimental results show that the stress and strain around the tunnel show nonlinear variation of the interval between the wave peak and the trough with the increase of the distance from the wall of the tunnel. It is verified that zonal fracture is a special failure mode under high axial stress. In the process of axial overloading, the surrounding rock begins to appear annular fracture, the strain increases rapidly in the annular fracture zone, and the strain decreases rapidly near the annular fracture zone. At the end of the overload, the strain around the hole shows the interval distribution between the wave peak and the trough, corresponding to the fracture zone of surrounding rock and the non-fracture zone respectively, and the radial stress around the hole also shows a similar change trend. The increase of the arch roof and the roof load of the model chamber will limit the range of the rupture zone around the model hole. The explosion load produces a large number of microcracks in the surrounding rock near the wall of the tunnel, which results in the deterioration and integrality of the mechanical properties of the surrounding rock, and under the condition of high axial in-situ stress, the microcracks propagate and pass through, forming a macroscopic fracture zone. The destruction of wall rock body is aggravated and the range of surrounding rock fracture zone is enlarged, and the radius of the latter layer is about 1.28 times of that of the former one. A three-dimensional particle calculation model for blasting excavation of deep rock mass is established. The numerical analysis of deep rock mass with different joint inclination is carried out, and the effects of time of explosion load and dip angle of layered joint plane on the zonal fracture of rock mass in deep underground engineering are revealed. With the increase of the inclined angle of the layered joint surface, the range of rock fracture area around the granular model hole after blasting excavation, the number of tensile and shear cracks and the strain energy increment show a trend of first increasing and then decreasing, when the dip angle of the layered joint is 600, The fracture zone of surrounding rock is the largest. The similar model test of blasting excavation of deep rock mass with anchor support under high axial in-situ stress is carried out. It is found that there is no zonal rupture in the joint support part of anchor rod and anchor cable, but there is a partition fracture in the unsupported part. It is concluded that the combined action of anchor rod and anchor cable can realize the stress transfer and redistribution of surrounding rock mass, and the mechanism of anchoring support to the zonal fracture of deep rock mass is revealed. Field blasting damage monitoring shows that the damage zone of the left side blasting is within 6 m, the right side blasting damage area is within 7 m, and the damage degree of surrounding rock is larger within 3 m.
【學位授予單位】：安徽理工大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TU45
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本文編號：2229461