三模式掘进机全断面岩层段TBM模式施工技术研究

为研究三模式掘进机使用TBM模式在全断面岩层中的施工技术,以广州地铁7号线二期萝岗站—水西站盾构区间工程为研究背景,分别从出渣方式、掘进参数控制、刀具管理和稳定器应用4个方面对三模式掘进机TBM模式施工技术进行总结。结果表明:1)本工程中三模式掘进机使用镶齿滚刀施工,相对光面滚刀的消耗更少,刀盘转矩更低;2)三模式掘进机TBM模式采用泥浆循环和螺旋输送机双通道出渣,可显著降低泥浆管堵塞的概率,提高出渣效率;3)三模式掘进机在前盾、中盾安装稳定器和撑靴,可保证全断面硬岩地层中掘进盾体不发生滚动,同时增强盾体稳定性;4)在全断面岩层中采用三模式掘进机TBM模式开挖隧道,刀盘转速为3.0 r/min,总推力约15000 k N,转矩可控制在1300 k N·m,推进速度为8~12 mm/min。

热带雨林地区全风化岩层基坑处理关键技术应用研究

神华国华印尼南苏1号2×350MW燃煤发电新建工程位于印尼南苏门答腊省,地势为丘陵斜坡地。工程地基主要持力层为全风化粘土岩,受环境因素影响强度迅速降低,导致施工难度、费用增加,且质量难以控制。热带雨林气候更加剧了这一挑战。为确保工程质量和进度,项目部与多方合作,形成完整的企业标准,解决全风化基岩施工关键技术问题。该技术对国内外同类型工程地基施工有广阔应用前景。

全风化岩层渣土改良对盾构隧道开挖面稳定性的影响

以佛莞城际铁路工程为依托,对泡沫改良渣土进行室内三轴快剪试验,分析不同泡沫比时渣土应力-应变关系和强度特性。建立基于计算流体动力学的三维流固耦合数值模型,分析泡沫比对开挖面支护压力、地表沉降的影响,以及渗透系数对孔隙水压力的影响。分析结果表明:泡沫比为20%的改良渣土比未改良渣土黏聚力减少9.72 k Pa,内摩擦角减少11.18°;开挖面纵向支护压力随着泡沫比的增大而减小;随着改良渣土渗透系数的增大,孔隙水压力明显减少;泡沫比越大,开挖面上方地表沉降越大。

板背隧道进出口段暗挖施工技术

针对浙赣铁路电气化提速改造工程板背隧道开挖断面大 ,进出口段通过第四纪强风化、浅埋岩层等特点 ,采用中壁法施工 ,挖掘机配合人工风镐开挖 ,以及大管棚、超前小导管、工字钢拱架、工字钢横撑相结合的支护加固地层技术 。

BTRK1型凿岩钻车在余吾煤业南翼轨道大巷的运用

余吾煤业公司南风井+400 m水平南翼轨道大巷设计为半圆拱形巷道,掘进断面32.2 m2,全长2 200 m,全岩巷施工。文章简要介绍利用凿岩台车在大断面、远距离巷道炮掘施工中的使用情况及效果。

Overlying strata movement rules and safety mining technology for the shallow depth seam proximity beneath a room mining goaf

Aiming at the shallow depth seam proximity beneath a room mining goaf, due to that the shallow depth seam is exploited using the longwall mining and overlain by thin bedrock and thick loose sands, many accidents are likely to occur, including roof structure instability, roof step subsidence, damages of shield supports, and the face bumps triggered by the large area roof weighting, resulting in serious threats to the safety of underground miners and equipment. This paper analyses the overlying strata movement rules for the shallow seams using the physical simulation, the 3DEC numerical simulation and the field mea- surements. The results show that, in shallow seam mining, the overburden movement forms caved zone and fractured zone, the cracks develop continuously and reach the surface with the face advancing, and the development of surface cracks generally goes through four stages. With the application of loose blast- ing of residual pillars, reasonable mining height, and roof support and management, the safe, efficient and high recovery rate mining has been achieved in the shallow depth seam proximity beneath a room min ing goal.

云南龙江大桥锚碇选型研究

悬索桥以其构造简单、受力明确、跨越能力大、造型美观等优势,在我国高速公路建设中得到了广泛应用。锚碇作为悬索桥的基础,对整座桥梁的安全有着重要的作用。本文针对云南龙江大桥的地形以及全风化岩层的地质情况,选择适合的锚碇型式,进行结构分析和方案比选,确定最优的锚碇方案,以期给类似地形地质条件下的悬索桥锚碇设计提供参考。

灰岩区不良地层下盾构施工技术难点研究

地铁隧道施工常用的盾构法在面对不良地层时存在一定施工难点。文章以广州地铁灰岩区某条线路的TS区间为例,分析TS区间的施工难点,针对全断面岩层裂隙和上软下硬岩层下的复杂管线,提出注浆封堵全断面岩层裂隙漏水,加固周边管线的解决方案。该方案有效减少盾构施工过程中的出渣量,减小地面沉降,为后续相似工程案例提供参考依据。

Numerical analysis of the destruction of water-resisting strata in a coal seam floor in mining above aquifers

With the increase in mining depth many mining areas in China have entered a period necessitating mining above aquifers. Production safety in coal mines in northern China is under serious threat from Ordovician karst water on coal seam floors, in order to analyze the destruction of water-resisting strata in floors of coal seams being mined and to achieve safe mining above deep aquifers, we established a numerical model of water-resisting strata, considering the structural characteristics and mechanical properties of a floor layered with hard and soft rock. We simulated the distribution characteristics of deformation, failure and seepage using the analytical module of fluid-structure interaction of FLAt：. We also obtained the corresponding stress distribution, deformation and flow vectors. Our results indi- cate that： （1） the advance of the working face causes water-resisting strata in goaf floors to form a deep double-clamped beam, subject to homogeneous loading at the bottom; （2） the two sides of the rock beam are subject 1~0 shear failure; （3） both sides of the rock seam at the bottom of the water-resisting strata are subject to tension and the greater the working face advance, the more serious the failure; C4） the original balance of the stress and seepage fields are broken and redistributed due to mining activities, especially the interaction of the abutment pressure in both sides of the goal; the lateral pressure on the goal floor and the water pressure on the floor of the aquifer promote floor heave and shear failure on both sides of the floor, forming a water-inrush passage. Our study results can provide references for the mechanism of water-inrush on mine floors.

Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams

Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions.

Safety Research on Filling Collapse by Dumping Rocks along the Collapse

Because the large collapse pits appeared in the surface of stoped-out area in the lower iron belt of the southeast of Gongchangling iron mine, the sliding danger of side wall of collapse pit threats seriously the production safety of open-pit of upper iron belt. The harm forms of collapse pit, especially the subsided harm of the bottom of granular media are analyzed. The experiment shows the possibility of the granular media forming the arch in the course of mining and analyzes the continuity of bulk movement. Then it can be concluded that the granular media of pit bottom will not suddenly subside in the process of downward shift. Therefore, a technical scheme of drawing the open-pit stripping rock along the collapse pit was proposed and the rock can be dumped along the collapse pit trend and wall safely.

Effects of overburden, rock strength and pillar width on the safety of a three-parallel-hole tunnel

During the excavation of three-parallel-hole tunnel, the tunnel might collapse due to over-stress as a result of inadequate rock pillar width. Treating the rock overburden depth, rock strength, and rock pillar width as variables, a series of 3D numerical analysis was carried out to examine the effect of each variable on the safety of the tunnel, in particular the rock pillar. A stress strength ratio (SSR) was used to define whether the safety of the rock pillar was exceeded. A simple design chart for the case of three-parallel-hole tunnel, which took into account the influence of overburden depth, rock pillar width, and rock strength, was also proposed for used in the preliminary design stage.