基于无人机贴近摄影测量的剖面数字露头系统研发及岩层面重构方法

针对大坡度、大规模的露头剖面考察中识别范围不足,面貌不全、人工依赖大、精度差、数据共享低的状况,使用无人机贴近摄影测量技术摄取露头剖面影像,建立毫米级精度的全景三维模型,采用Web GIS技术,自主研发网络版数字露头平台,实现露头数据的共享。为重构某一局部岩层面,三维模型表面需建立一个贴面。数字地球引擎Cesium内置方法、边界面法建立贴面时,出现了贴面范围不准确、内部不连续的问题,提出一种在Web虚拟场景上充分利用空间场景几何特征与空间距离度量关系,自动判定岩层剖面特征点的新方法。特征点作为加密点在空间范围内构建三维Delaunay三角网,准确标定出某一岩层范围,实现了剖面岩层的重构。结果表明,该方法重构的岩层范围正确,内部连续,结果清晰,为地质资料知识库构建提供辅助手段与数据支撑。

基于单元划分的复杂岩层面三维建模方法研究

针对现有岩层面三维建模方法未系统考虑含断层、陷落柱等地质条件的复杂岩层面三维模型构建的问题,通过定义投影度和投影单元,给出了不同地质条件下岩层面水平投影单元特征,同时提出一种基于单元划分的复杂岩层面三维建模方法。先划分岩层面水平投影单元和空间插值单元,将水平投影单元边界、空间插值单元边界、岩层面控制点和控制线作为约束条件,对实投影单元进行约束Delaunay三角剖分;然后分别求解各个空间插值单元内三角网顶点对应的岩层面空间插值点,并应用计算机三维图形技术绘制岩层面三维图形。实例分析结果表明,通过划分水平投影单元和空间插值单元,可将复杂岩层面分解为多个一般岩层面,从而降低其三维建模难度;合理进行约束Delaunay三角剖分和空间插值,可有效构建复杂岩层面的三维模型。

重力坝沿岩层结构面的抗滑稳定分析研究

一般情况下重力坝的抗滑稳定分析在前期阶段已经进行了详细计算,但是当拦河坝基础开挖完成后,根据实际揭露的地质条件,虽然大坝建基面整体性和完整性较好,基岩岩层虽倾向上游,但倾角较缓,层面较为明显,对坝基岩体表层抗滑稳定不利,需对坝体沿岩层结构面的抗滑稳定进行进一步计算分析。并根据计算分析结果,采取必要的处理措施,以保证坝体稳定和安全。

急倾斜煤层煤岩结合弱面巷道锚网支护快速掘进技术

针对煤岩层结合弱面巷道顶部三角煤易离层脱落的支护难题,运用非弹性区域应力理论,计算选择锚网支护参数,采取工程进度控制的关键线路法优化施工工艺,实践并总结出了急倾斜煤层煤岩结合弱面特殊条件下巷道快速掘进工艺技术。

顺层岩质边坡稳定性影响因素分析

层状岩体抗剪强度具有各向异性的特点,在分析顺层岩质边坡的稳定性与剪切滑动面方向上需要考虑 c,Ψ值方向性变化的影响。首先提出层状岩体 c,Ψ值的表达式,然后在此基础上选用一顺层边坡作为实例,分别计算分析了坡高、岩层面倾角、坡顶堆载特别是强度参数 c,Ψ值各向异性对边坡稳定以及剪切面方向的影响。

用向量代数代替等角投影求解地质构造中的一些角度问题

在研究地质构造时,常常遇到一些角度问题,例如,二岩层面的交角、二岩层面交线的走向与倾斜,这些角度的求解一般都是根据野外测量所得各岩层面的走向与倾斜,采用基于等角投影原理的图解法求得。由于这种图解法简单易行且具有一定的精度,所以长期以来为人们普遍采用。但此法不足的地方是绘图、量测都带有一定的误差,致使结果不尽理想。本文则是用向量代数代替等角投影解决上述角度问题,目的仅在于弥补图解法的不足。

“解读主要地质灾害”教学设计(湘教版)

一、教材分析“解读主要地质灾害”是湘教版高中地理教材选修V《自然灾害与防治》中自然地理知识最集中、涉及面最广的一个单元。地质灾害的种类很多,从课时容量考虑,教材有选择地讲述了地震、滑坡和泥石流等地质灾害的成灾原因及灾害本身的基本知识、危害、地质灾害之间的关系以及地质灾害的防御等内容。本节教材的特点之一,注重知识的实用性及其与人们生活生产关系的密切程度;特点之二,从有利于学生认识地理环境的角度出发,

山区岩体中特种结构的震害及抗震特性研究

基于对汶川地震中遭受破坏的山区岩体中特种结构的现场震害调查,研究了岩体中结构的震害宏观现象和机理;建立基于波动理论的有限元数值模拟方法,分析了山区岩体中结构的地震响应及其受岩层结构面和断层带的影响。

红砂岩力学性能室内大型直剪试验研究

红砂岩在风化崩解过程中,抗剪强度大幅降低,易引起红砂岩质边坡顺层坍滑。为研究其边坡滑塌的力学机制,采用单点法在边坡软弱岩层位置取样、制样,并通过室内大型直剪试验来模拟红砂岩岩层结构面的摩擦剪切情况。试验结果表明:未风化崩解的红砂岩块经历多次干湿循环,其岩层界面的力学性能显著下降,并由此导致其边坡失稳。

Protection Measures for Buildings Based on Coordinating Action Theory of Ground, Foundation and Structure

Based on the theory of coordinating action of building ground, foundation and structure, this paper presents a modified method for calculating additional stresses on buildings in mining areas by considering the joint effect of cur- vature deformation and horizontal deformation on buildings. It points out that for buildings over the coal pillar, it is ad- visable to soften the intermediate ground of buildings when they are affected by mining. For buildings over the goaf, it is preferable to soften the ground at both ends of buildings. In order to enhance the ability of a building to resist tensile deformation, the key measure is to reinforce the bottom foundation of the building. In addition, the concept of “angle of break of building” is proposed. It is because of this angle that the protecting coal pillar is left, which is a better solution than prevailing solutions The findings provide a more scientific basis for mining under buildings.

Surface Movement Regularity of Super-Wide Mining Face With Top-Coal Caving

No.4326 super-wide panel of Wangzhuang Coal Mine ( in which the fully-mechanized top-coal caving longwall mining method was used) was monitored for dynamic characteristic of surface movement. The dynamic surface movement in and after mining was predicted by using the Mining Subsidence Prediction System. The results indicate that after mining, the surface above the super-wide panel reaches a state of full subsidence, making the No.309 national highway above the panel be located on the flat bottom of the subsidence basin so that the influence of mining activity in both sides of 4326 panel on the national highway is the smallest.

Ground pressure and overlying strata structure for a repeated mining face of residual coal after room and pillar mining

To investigate the abnormal ground pressures and roof control problem in fully mechanized repeated mining of residual coal after room and pillar mining, the roof fracture structural model and mechanical model were developed using numerical simulation and theoretical analysis. The roof fracture characteristics of a repeated mining face were revealed and the ground pressure law and roof supporting condi- tions of the repeated mining face were obtained. The results indicate that when the repeated mining face passes the residual pillars, the sudden instability causes fracturing in the main roof above the old goal and forms an extra-large rock block above the mining face. A relatively stable ＂Voussoir beam＂ structure is formed after the advance fracturing of the main roof. When the repeated mining face passes the old goaf, as the large rock block revolves and touches gangue, the rock block will break secondarily under overburden rock loads. An example calculation was performed involving an integrated mine in Shanxi province, results showed that minimum working resistance values of support determined to be reason- able were respectively 11,412 kN and 10,743 kN when repeated mining face passed through residual pillar and goaf. On-site ground pressure monitoring results indicated that the mechanical model and support resistance calculation were reasonable.

Model on surface borehole squeezing deformation fracture

As a good method to solve the problem of high methane on the workface and inthe goaf,drawing coal strata methane through a surface borehole is used.However,theexcavation affected the overlying rock strata greatly.When the excavation face passedthrough the surface borehole position,the surface borehole fractures fast.This problemwas seriously related to the unformed squeeze effect.Therefore,a squeezing deformationfracture model based on the rock strata squeezing effect was set up.At the same time,a3DEC simulation model is presented to confirm the theory.The result shows that the modelis reliable and has a good engineering application value.

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.

Visco-elastic Properties of VES Diverting Acid for Carbonate Reservoirs

Storage modulus and loss modulus is the main performance index of visco-elastic properties.In this paper the storage modulus and loss modulus of a new diverting acid and their influencing factors were systematically investigated.Besides,the constitutive equations of the diverting acid at different temperatures were elicited from shearing experiments,which show that the visco-elastic surfactant(VES)acid system is a non-Newtonian power law fluid at low temperature and a Newtonian fluid at high temperature.The storage modulus and loss modulus at different temperatures,pH,and VES content in the acid are critical for the design of acid stimulation for oil well,especially when the VES acid is used in this field only on trial and the basic data are in urgent needed for the design and construction of the acidification stimulation.

Investigation on displacement field characteristics of tunnel's surrounding rock and coal seam at FMTC face

The change rules of displacement field characteristics of coal seam and tunners surrounding rock were obtained by means of numerical simulation-FLAC^3D and site observation, and according to engineering geology and exploitation technology of 1151 （3） fully mechanized top coal caving （FMTC） face in Xieqiao colliery. The research＇s results show that the top coal displacement on the top of FMTC face is apparently larger than those of the middle and the bottom, the top coal begins to move in the front of the face＇s wall, and the sub-level top coal-rock moves ahead of the low-level top coal-rock, the vertical displacement of top coal-rock increases gradually as the decreasing of distance to face Top coal and overlying strata in vertical direction are always in compressed state in the front of face, then the top coal begins to separate from the overlying strata at the upside of face. The support loading at face is mainly the deformation pressure due to top coal and main roof＇s movement, and it is not suitable for the FMTC face with traditional support design. Surrounding rock movement of the face is of near-field effect, the surrounding rock deformation is acute greatly near to the face, the ideas of supporting design for the tailentry and headentry should be changed from loading control to deformation control.

Rock mechanical investigation of strata loading characteristics to assess caving and requirement of support resistance in a mechanized powered support longwall face

Longwall mining is one of the most acclaimed and widely used in underground method for coal extraction. The interaction of powered supports with the roof is the key issue in strata mechanics of longwall mining. Controlled caving of rock mass is a prerequisite pro thriving exploitation of coal deposits by longwall retreat with caving technique and support resistance has evolved as the most promising and effective scientific tool to predict various aspects related to strata mechanics of such workings. Load density,height of caving block, distance of fractured zone ahead of the face, overhang of goaf and mechanical strength of the debris above and below the support base have been found to influence the magnitude of load on supports. Designing powered support has been attempted at the different countries in different methods. This paper reviews the mechanism of roof caving and the conventional approaches of caving behaviour and support resistance requirement in the context of major strata control experiences gained worldwide. The theoretical explanation of the mechanism of roof caving is still continuing with consistently improved understanding through growing field experiences in the larger domain of geo-mining conditions and state-of-art strata mechanics analysis and monitoring techniques.

Characteristics of compression fracture of ＂three soft＂ coal bed by perfusion and gas sucking technique

Against the particularity of stratum-structure in ＂three soft＂ mine areas, according to rock indoor test and on-site sucking experiment, discussed the characteristics of argillization, compression fracture and sucking technique of soft coal with low permeability. It is clearly pointed out that the gas can be highly effectively sucked only by compression fracture along the occurrence of the coal seam, creating inter-seams crack belt because of the difference of bulgy deformation. After the flooding experiment in the 24080 workface of Pingdingshan No. 10 mine, the average single-bore volume of gas increases from 77 m3 to 7 893 mS, while decay cycle extended from 7 days to 80-90 days. Also, the single-bore extracting rate of gas increases to 33%.

Study on the distribution of strata rock temperature around a driving head with auxiliary ventilation

The distributions of strata rock temperature around a driving head with auxil- iary ventilation were analyzed theoretically based on a program which was developed by the authors to predict the thermal environmental conditions in a development heading with forcing auxiliary ventilation. The influences of wetness of the airway surface were dis- cussed on the cooled zone of the strata rock and on the temperature distribution in the surrounding rock. It is shown that the advancing speed and driving time have little influ- ence on the temperature profile in front of the working face of a driving airway, and the rock temperature 1.5 m ahead of the working face can be taken as the virgin rock tem- perature.