THE MEASUREMENT AND STUDY OF BLASTING VIBRATION AFFECTING IN SITU CAST CONCRETE LINING OF VERTICAL SHAFT

Vertical shaft is main form of drivage in deep mineral depoist. They also serve as the entrance into and the exit from the underground mine. The main problems in shaft and tunnel engineering is to solve the contradiction between drivage and lining. The measurement of blasting vibration affecting concrete lining strength of vertical shaft is carried out in experiment and theory in this paper.     

STUDIES ON VERTICAL SHAFTLINING STRUCTURE ADAPTABLE TO SUBSIDENCE

Subsidence results in a negative force of friction on the outer surface of the shaft lining. This negative force has in recent years led to damage or even destruction of over 20 shafts. In the light of this shaft failure mechanism, analytic comparison is conducted on three shaft lining structures as to their respective behaviour under the negative force of friction, by making use of modelling tests. A new shaft lining structure is therefore proposed which is designed to be adaptable to subsidence and found to be rational. Finally designing principles are given.     

MECHANICAL ANALYSIS OF SHAFT LINING WHEN THE STRATUM SETTLEMENT RESULTING FROM WATER DRAINAGE

Based on the stratum settlement resulting from water drainage, this paper establishes the calculating method of stresses and displacements of shaft lining and stratum by using Fourier integration, obtains the calculating formulas of tangiential load which shaft lining is subjected to, and provides theoretical basis for design of shaft lining.     

THE MINED NONLIEAR STUDY OF MEASURING METHOD AND CALCULATION ABOUT STRESS AND STRAIN IN THE VERTICAL SHAFT AD SURROUNDING ROCK

The damage of the overburden is a complex nonliear mechanical problem. To immediately master the stress state of the vertical shaft in process of the damage of overburden, andprotect the shaft, in this paper, a series of new type of rock mass stress and strain compatiblesensors are used. The vertical shaft wall mechanical parameter and surrounding mechanical pa-rameter are calculated by the result of the measurement. A set of the calculation method of thevertical shaft and surrounding rock parameter are defined.     

THE FEM ANALYSIS OF SHAFT UNDER THE NON-AXIAL SYMMETRICAL LOAD

The changes of stress and strain around the shaft under the non-axial symmetrical loads during the excavation are analyzed with the finite element semi-analytical method based on the separated variable method. The change laws of deformation and stress of surrounding rocks are obtained. Moreover, an optimum method of the design and construction of the shaft lining is developed, which presents a new train of thought of the design and construction of the shaft and has important theoretical value and extensive application prospects.     

Research and development on cutting scale machine in the coal mine shaft

The deposit scale in the coal mine shaft usually causes serious accidents, such as making rope broken, cage seized or dropped. To solve this kind of problems, the research of the cutting scale mechanism was made, and a new type of removal scale equipment was made with using imported hard alloy material. The cutting experiment and actual cutting show that it can adapt to abominable condition in the shaft, such as narrow space, wet and excessive shaft crevice water and so on, and can work safely and reliably,and has high cutting scale efficiency. It can also cut out the deposit scale in the circular section of shaft.     

COMPREHENSIVE DESIGN METHOD OF FREEZE WALL AND ITS APPLICATION

Artificially ground freezing (AGF) is one of the main methods to establish temporary support for shaft sinking in unstable water bearing strata. Domke(1915) formula based on frozen soil strength has widely been used for designing freeze wall thickness. However, it can not ensure the stability of freeze wall, nor guarantee the safety of shaft construction as frozen depth increase in unstable water bearing strata. F.A.Auld (1985, 1988) presented a design method of freeze wall, which is on the basis of strength and stability, together with deformation of freeze wall.He combined deformation of freeze wall, lining and deformation of freeze tube to set up a comprehensive design method for freeze wall. This paper, according to the practice in China, describes a comprehensive design method for deep freeze wall, considering influence of excavation rate of advance, unsupported length of freeze wall and the sump state on inward deformation of freeze wall, and the allowable pipe deformation caused by inward deformation of freeze wall. Finally, successful application of this method to the large scale coal mine-Jining No.2 Mine in Shandong Province of China, is presented.It saved much investment compared with F.A.Auld‘s design for the same mine on behalf of Shell Coal International.     

PLASTIC LIMIT ANALYSIS OF DISCONTINUOUS LINING UNDERGROUND PRESSURE

Discontinuous lining is a special form of support in underground excavation. Based on the method of plastic limit analysis, it is found the upper and the lower bound solution of the pressure of circular discontinuous lining and discussed support parameter of discontinuous lining and its applicable conditions, which provides theoretical basis for the design and calculation of discontinuous lining.     

SUPPORTING PROCEDURE AND FIELD MEASUREMENT IN THE SHAFT THROUGH GLIDING TECTONIC GROUND

The paper describes mechanical properties and deformation features of shaft adjoining rocks in gliding tectonic ground and presents the shaft-fupporting procedure of smooth-wall cushion blasting ,preliminary bolting and shotcreting and pouring reinforced concrete liner in one-time-whole-section in the basis of adjoining rock deformations measured dynamically in site ,Field measurements of the pressure exerted on shaft wall show that this supporting procedure has enough safety reserve to meet the safety repuirements in mining production.     

THE MODEL TEST RESEARCH OF HORIZONTAL FORCE ON RIGID SHAFT FURNITURE IN DEEP MINE

The state of deep mine rigid shaft furniture horizontal force calculation in China isintroduced and the calculating model of horizontal force is determined. Based on the interactionbetween hoisting vessel and shaft furniture, the vertical model test device is built and a largenumber of model tests and analyses are carried out. At last, the relationship between horizontalforce and hoisting end load, hoisting speed or bunton level interval is gained. The threeparameters horizontal force calculating equation of deep mine rigid shaft furniture is given and itcan guide the design and calculation of shaft engineering.     

采空塌陷区立井井壁结构的研究与设计

针对在采空塌陷区修建立井井壁的技术难题,以淮南新庄孜矿技改新增副井、回风井为例,对两井筒过采空塌陷区的关键层位井壁结构,采用柔性、让压、可缩性钢纤维混凝土复合井壁.通过试验,获取了钢纤维混凝土和沥青滑动层的最优配合比,并对竖向可缩性接头的结构形式和参数进行了设计.     

塑料板夹层双层井壁的轴对称变形分析

针对特殊地层中的塑料板夹层双层井壁结构,应用空间轴对称问题的弹性理论建立了相应的受力分析方法。综合运用线性叠加原理、弹性通解、Fourier方法等理论,获得了该双层井壁在一般荷载条件下的一组圣维南解。通过算例分析了内壁、外壁厚度的改变对井壁环向、径向及轴向正应力的影响,并利用第四强度理论分析了立井安全性的变化。结果表明：仅增加内壁厚度对井筒内、外壁安全性的提高均不显著;仅增加外壁厚度对井筒内壁安全性的改善较小,但对于井筒薄弱环节外壁安全性的提高则较为显著。     

单层井壁竖直附加力变化规律的数值分析

深厚表土疏排水沉降地层条件下的井壁处于复杂的动态受力状态,井壁的受力变化主要与底部含水层的渗透系数、含水层固结沉降量、井壁与国土的耦合作用有关.为探讨井壁竖直附加力大小的变化规律,运用数值模拟方法对单层混凝土井壁进行了分析研究,得出:井壁的竖直附加力与底部含水层渗透系数成正比对数关系,与井壁混凝土的弹性模量成正比线性关系;同时发现复合载荷作用下井壁的应力应变关系是动态变化的,井壁的塑性区是多种载荷耦合作用的结果.因此,减小底部含水层的渗透系数、井壁混凝土的弹性模量,有利于减小井壁的竖直附加力,可提高井壁的可靠性.     

含水不稳定基岩段新型单层冻结井壁结构及抗渗研究

单层井壁较我国普遍采用的双层井壁结构形式有施工工期短,成本低等优点。提出了在煤矿立井穿过含水不稳定基岩段时,可采用单层井壁结构。针对单层井壁存在施工冷缝且受到地下水压力和多向应力的作用出现渗(漏)水的问题,研制出了一种用膨胀混凝土和类S形接茬方式浇筑的新型单层井壁结构形式。根据相似理论进行了井壁结构模型设计和模型试件的加工制作,并做了相关的模型试验。研究结果表明,此种新型单层冻结井壁在环向压力和竖向压力共同作用下的抗渗性能良好,所以单层冻结井壁在井壁结构施工中具有一定的可行性。     

特厚表土层钻井井壁底结构分析与设计优化

针对目前特厚表土层深钻井工程井壁底常用设计计算方法不能反映结构的细部应力特征、且支承环应力与实际状态不符的难题，采用有限元法对淮南张集煤矿西区进风井井壁底结构进行了数值分析，计算结果表明，原设计井壁底结构中壳体与支承环相交处内缘径向应力最大，为-34.54 MPa.在井壁底结构设计时，可取支承环高度2.0 m进行计算.通过设计优化，井壁底结构中最大应力得到大大降低，只有-12.68 MPa，满足了设计强度要求.工程实测结果表明，优化后井壁底结构中实际钢筋的最大应力为-67.20 MPa，混凝土最大应变为-351 με，且都远小于他们的设计值.优化后的井壁底不但节约了混凝土浇灌量，更为重要的是中间部位没有浇灌实，为后面破锅底爆破工作创造了自由面，加快了施工进度.     

冻结法成井井壁在深厚表土段附加应力研究

为研究深厚表土段井壁的破坏机理,提高井筒的使用寿命,指导已破坏井筒维修和为新设计井筒提供依据,采用数值模拟和理论计算相结合的方法,对淮北煤田深厚表土段井壁附加应力的产生原因及大小进行了探讨。结果表明：附加应力由井壁和裹携土体重量产生,与地下水埋藏深度、土的容重、地下水层数有关,地下水埋藏越深,产生的附加应力越大,在基岩表面处的附加应力为89.91 MPa,远远超过了混凝土井壁的抗压强度。为避免井筒破坏,应采用方法是：增加井壁强度、保持原有水压、设法减少锥体的重量、井壁在应力集中处采用伸缩装置。     

双卸压槽法修复破裂井壁的试验研究

为了揭示双卸压槽修复破裂井壁的机理,采用对比方法,通过设置双卸压槽的井壁试件与未设卸压槽的普通井壁试件的模型试验,对此问题进行了研究。研究结果表明:对于设置双卸压槽的井壁,双卸压槽的压缩变形可有效地衰减井壁附加力,确保井壁安全;对于未设卸压槽的井壁,井壁竖向变形很小,极易破坏。     

高强混凝土在立井井壁中的应用及展望

高强混凝土是一种品质优良的建筑材料，具有强度高、变形小、良好的抗渗性和抗冻性。将高强混凝土用于深厚表土层立井井筒工程中，能满足我国不断加深的钻井和冻结井简建设的需要。高强混凝土复合井壁具有减小井壁厚度，防止井壁渗水，降低建井成本的优点。介绍了我国煤矿立井使用高强混凝土所取得的经验，提出了今后深厚表土层中高强混凝土复合井壁的结构形式，以便更好地推广和应用高强混凝土井壁，解决深厚表土层立井支护的难题。     

附加力和温度共同作用下井壁附加应变变化规律

以华东地区姚桥煤矿老矿主井井壁安全监测系统的实测资料为基础,通过对实测附加应变、井壁温度及地表沉降结果进行综合对比分析,结合井壁受力特点,得出井壁附加应变变化规律.井壁附加应变受竖直附加力和温度共同作用,在数值上表现出正弦波动并逐渐积累的态势,具有明显的周期性和可预见性.     

复合井壁技术在淮北矿区的应用和发展

本文较详细地总结了淮北矿区复合井壁由试验到推广应用的发展过程,系统地总结了复合井壁发展各个阶段的技术特点及其取得的社会与经济效益。并在此基础上阐述了复合井壁产生与发展的必然性。文章通过对大量现场观测资料与数据的分析,重点揭示了复合井壁中砌块、中间夹层、泡沫塑料板、夹层注浆、无壁座施工等各个环节的作用机理和井壁不裂不漏的客观规律。文章还进一步展望了深井冻结施工井壁结构的发展前景,提出了合乎我国国情的井壁增强减薄的具体途径。并就采用硅粉混凝土增强减薄井壁提出了建设性意见。