附录 1
井筒及巷道的支护
井筒的支护
在国外，很少使用砖、料石和铸铁井壁， 从前，几乎全用木支架，但现在混凝土和金属井壁使用量日增。 井壁的选择决定于围岩和水的条件，井筒的形式和材料的费用。
(1)木支架——直到最近，大多数方形的井筒还在用框形木支架支护井帮和分成隔间。.所用木料的尺寸和框距取决于所遇到的岩层情况。. 木支架缺点是费用高，强度低、寿命短，易引起火灾。在膨胀性岩层中，木支架损坏得慢，警告时间长。在大多数情况下，开始凿井时浇灌一个混凝土锁口以固定支架，为井筒木支架提供良好的基础。木框架一般用挂钩挂在上面的框架上，框架就位后插入支柱，拉紧挂钩，在井筒周围铺上背板。
(2)金属支护——有时用金属支架代替木支架。 通常与木背板配合使用。木背板可快速而高效地插入金属支架的翼缘中。金属支架若设计恰当其安装的速度和准确度均比木支架高，因为安装时金属支架可能螺栓连接，并且排列很整齐。
(3)混凝土井壁——现在，原形混凝土井壁使用日益广泛。 例如，在南非几乎100%的井筒采用圆形混凝土井壁。而且几乎所有井筒毫无例外地达到最高的凿井速度。 除了凿井速度快外，，还有许多其它优势。 圆形混凝土井壁做井筒指甲其强度系数最高，风流特性最好，与任何井壁形式相比其维护量最小。混凝土井壁容易拆除并改装成另一种提升布置方式，或改为风井而不影响围岩状态。这类井筒对涌水的控制或封堵容易的多。与大多数其他类型相比，这种井筒的事故较少，万一发生事故，修复也容易得多。在某些特殊的情况下，也采用方形或椭圆形混凝土做井壁的井筒。尽管方形井筒的成本与圆形或椭圆形相仿，但其强度不如圆形或椭圆形井筒。椭圆形井筒具有良好的强度系数，需要分开风流时采用这种形状。但起凿井费用比圆形的高。
(4 )喷浆或喷射混凝土井壁——有一些井壁采用喷浆或喷射混凝土井壁。这类井筒的罐道一般用锚杆固定。如果井筒完成后并能不需要罐道，那么凿井时可采用钢丝绳罐道。
巷道支护
过去，框形或多节木支架是大家熟悉的唯一支护井下巷道的方法。随着坑木的减少，宽翼缘型的出现，钢材，作为一种结构支护材料，迅速的取代了坑木。最近锚喷支护也列入矿山实用支护方式。不论锚杆还是喷射混凝土（包括喷浆及喷混凝土在内）一英尺巷道的支护费用一般比金属支架要低。有时两者同时采用，其费用也比金属支架省。
(1)金属支架——金属支架通常由两节组成，每节包括一条棚腿和半截拱。同样两节相对立好之后，在拱顶用螺栓对接。金属支架的尺寸取决于岩石的性质和地压。一般地说，小断面巷道采用4英寸或5英寸金属支架，间距为1.5—4英尺；中断面巷道采用5~6 英寸金属支架，间距为1.5—4英尺；大断面巷道采用6~8英寸金属支架，间距2~5英尺。对于全部采用锚喷支架的工程，只是在断层和严重破碎或软岩地带才需用金属支架。根据需要，金属棚子还必须铺以木档块及木背板。一个标准掘进班组架设一架金属棚子，需时20~40分钟。
(2 )锚杆支架——现在通用的能张紧的锚杆有许多多种，其主要区别在于，拧紧螺帽使锚杆张紧之前，在孔内固定锚头的胀圈结构的不同。最适合某种岩石的锚头形式要经常做试验来确定。软钢金属锚杆的直径至少应为1英寸，长度应为10英尺（巷道断面要足以允许使用这样长的锚杆）。安装锚杆时应认真研究岩石节理的规律。锚杆的布置要大致均匀有规律，使锚杆张紧之后能与围岩构成一个相似的拱形结构，以承受作用在巷道上的外部压力。在起拱线以上整个巷道顶板锚杆的平均间距在最小约12平方英尺/根，最大25或25以上平方英尺/根之间变化。由普通掘进班组安装锚杆时，一个标准掘进班组通常在30至40分钟内可安装锚杆，一个小时也许只能平均安装两根。
(3 )喷射混凝土——喷射混凝土或喷浆，这种把混凝土或砂浆直接喷到拱形巷道顶板岩石表面的方法正迅速地被公认是一种效率高而又经济的巷道支护方式。只要喷上的混凝土能附着相当时间达到初凝强度而不陷落，此方法在各类软、硬岩石或硬土上均可用。有许多促凝剂可到初凝。混凝土的喷射厚度为2~6英尺。干法喷射的效果通常比湿法好，因为可以喷、得厚一些，可以采用较大粒度的骨料（最大为0.75英寸），每台喷嘴的小时生产率较高（一个小时达5立方码）。喷射混凝土在经济上常具备的优点之一是可在装岩的同时，向巷道顶板喷混凝土，从而缩短完成整个“循环”所需用的时间。
木支架
掘进中也许需要支护巷道顶板和两帮的支架。传统的方法通常是掘进时先架设临时木支架，然后换成永久支架或衬砌。永久支架也可用坑木。
坑木作永久支架时应该很好地晾干并用防腐蚀剂处理。木支架不用专用的工具或设备就能方便地就地加工很快地架好，通过局部不良地层掘进时，用木材作临时支架，容易截割和加工，适应各种需要。
木棚是由几根坑木构成、横截巷道断面的支架。小断面巷道最常用的是三个构件组成的棚子，由一根顶梁（横梁或棚梁）架在两个棚腿上组成。棚腿倾斜度是每英尺1—1.5英寸，这样的斜度除非侧压力太大及底板松软，一般能防止棚腿底部向里推移。棚腿一般为硬木，圆形，小头的最小直径为5英寸。顶梁最小厚度一般为5英寸，宽度6—8英寸。背板一般厚2英寸，两帮和顶板上可铺也可不铺背板。
在膨胀岩层中两棚腿底部一般有“偏坡底撑”以防止棚腿移动，底板易隆起的地方，可采用反拱支架。巷道的悬顶（或顶板）如果做成拱形往往比较稳定，特别是在宽巷道中更是如此。只有顶板需要支护而两帮坚硬的地方，可以省去棚腿，拱梁则固定在起拱线处的梁窝中。支架木料的尺寸和棚架间距取决于巷道的断面和所需承受的压力。在膨胀岩层中，背板不要铺得太密，相邻背板之间应留一定间距，以释放低压。
装设木支架的常规工序和速度主要取决于支架在工作面后面应保持多近的距离。如果每进一个循环需要立即支护，那么架设支架就成为掘进循环的一部分。爆破后的第一道工序是撬落顶板上的浮石；在松软的地层中，利用前探梁、滑梁或类似的装置以支护最后一架棚子前面的顶板，以便装岩时保护工人。一个循环的矸石装完后，就架设新棚子，必要时用楔子固定并装上背板，并为新的循环安装好凿岩机。这种工序显然会减慢掘进速度，但是除非岩层条件太差需要才用前探板桩法或其他方法，一般坑木可标准化，并采用常规作业。作业开始之前，将所有材料和器材运到工作面，可加快速度；工人应携带整架棚子、角楔、木楔、背板和工具进入工作面。支护工作落后于工作面过远的地方，一般需要专业支架队。利用适当的工作台进行支架工作，可不影响掘进工作。如果采用移动式工作台，其台面有几架棚子长，其高度又能让矿车从底下通过，则对掘进工作会有好处的。
附录2
GROUND SUPPORT FOR SHAFTS AND TUNNELS
In the USA, brick, stone and cast iron shaft linings are rare; formerly, timbering was almost universal but concreting and steel framing are increasing in use. Choice of support depends on ground and water conditions, shape of shaft and cost of materials.
(1)Timber Sets——Until relatively recently, most rectangular shafts have used square-set timbering for ground support and compartment division .Size of the timber used and set spacing is dependent on ground conditions encountered .The disadvantages of timer sets are the cost, strength , short life and fire hazard involved. In swelling ground timbering fails slowly and with ample warning .in most cases , a concrete collar is poured at the start of a shaft to tie the sets in and provide a good bearing for the shaft-timbering installation .Timber sets usually are hung from the preceding set with steel hanging rods .After the set is in place , the posts are inserted and the hanging rods are tightened up . The lagging is placed in around the sides of the shaft.
(2)Steel Sets-Steel sets sometimes ate used instead of timber. Wood lagging generally is employed in conjunetion. The laggling can be placed in the web of the steel sket very quickly and effectivelt. Properly designed steel sets go in faster and more accuratelt than wooden sets, as they can be bolted together and lined up perfectly when assembled.
(3)Concrete Lining-Circular concrete-lined shafts are more and more used today. For example, in South Africa, almost 100% of the shafts installed are circular concretelined .Also almost without exception, the best sinking time is achieved. Besides the good sinking rate, there are numerous other advantages. The circular concrete section provides the greatest strength factor for ground support ,the best air-flow characteristics, and by far the lowest maintenance of any shaft type. It can be stripped easily and changed to another hoisting configuration, or to a ventilation shaft, without disturbing ground conditions. Water can be controlled or sealed off much easier in this type of shaft. There are fewer wrecks in this shaft than in most other types, and rehabilitation can be accomplished much easier if they do occnr. In some special cases concrete-lined shafts of a square of elliptical shape are used. Although the cost is similar, the square shaft does not have the strength of either the circular of elliptical. The elliptical shaft has a good strength factor and is used where split ventilation is required. It is, however, more expensive to sink than a circular shaft.
(4)Gunite or Shotcrete Lining——There have been some shafts sunk using gunite or shotcrete for wall support. The guides in this type of shaft usually are not required in the completed shafe, the rope guides could be used in sinking.
GROUND SUPPORT FOR TUNNELS
In former years, the square or segmented timber set was the only known method for supporting underground excavations. As timber become more scarce and wideflange steel shapes made their appearance, steel rapidly displaced timber as a structure-support material. More recently, rock bolting and pneumatically applied concrete have been added to the list of practical ground-support media. Either rock bolting or pneumatically applied concrete concrete usually cost less per linear foot of tunnel than steel ribs . Sometime the two are used together and still show a saving over steel ribs.
(1)Steel Rib Support-Steel rib sets commonly are fabricated in two pieces with the side leg and half of the arch in each piece. The two identical pieces are stood up and bolted together at a butt joint in the crown . Size of steel required will depend upon the nature of the rock and the pressure being exerted by the ground . Generally speaking, a small tunnel section will require a 4-or 5-in .rib with spacing of 1(1/2)to 4ft; medium-sized , 5-to 6-in. rib with spacing of 1(1/2) to 4 ft; large, a 6-to 8-in.rib with spacing of 2 to 5 ft. On a project where full utilization is being made of rock bolting and pneumatically applied concrete, steel rib supports need be used only in fault zones and through stretches of badly broken rock or soft ground. Supplementing the steel rib, timber blocking and lagging must be installed as required. A standard tunnel crew usually erects a set of steel in 20 to 40 min.
(2)Rock Bolting –A number of types of tensionable rockbolts presently are available , differing mostly in the arrangement of the expandable device which anchors the end of the bolt to the rock prior to applying the tension by tightening the nut. Experimentation frepuently is necessary to determine the type of anchor most suitable to a particular formation of rock. Mildsteel bolts should be at least 1 in. in dia and 10 ft long, provided the tunnel is large enough to permit insertion of rods of this length. Rockbolts must be installed with careful consideration for the jointing pattern of the rock.. They must also be installed in a more or less uniform and regular pattern so that when tensioned they will, with the surrounding rock,produce a homogeneous arch structure against the external stresses acting upon the excavation opening. Average spacing of the rockbolts, throughout the roof of the tunnel above the spring line, will vary from a minimum of about 12sq ft of rock per bolt to a maximum of 25 or more. When rockbolts are installed by the regular tunnel crew, a standard tunnel crew usually will install the bolts required for one full round of advance of 8ft in 30 to 40 min. If a two-man crew alone is installing bolts, they probably will average two bolts per hour.
(3)Pneumatically Applied Concrete—Shotcret or gunite, applied directly to the rock surface of the arched tunnel roof, is rapidly becoming accepted as an effective and economical means of ground support. It can be used in all types of fair to poor rock or firm earth provided the material will stand up without caving for a sufficient time to permit the sprayed concrete to gain its initial strength. Accelerating additives are which, when added to the concrete at the spray nozzle, will cause initial set to occur within 3to 10 min. after the mortar has been applied. The concrete is applied in thickness of 2to 6 in. Dry-process application usually produces better results than the wet process because it permits the placing of thicker layers, uses larger aggregates (maximum, 3/4 in.) and usually achieves a higher production rate per hour per nozzle (to 5.0 cu yd. per hr). One of the economies which frequently can be achieved with pneumatically applied concrete reflects the fact that it can be applied readily to the tunnel roof during the mucking cycle, thereby shortening the total time required to complete the “round”.
TIMBER SUPPORT
Supports for the tunnel roof and sides may be required while driving. Conventionally, temporary timbering is often used during driving and replaced later by permanent supports or lining. Permanent supports may be of timber too.
For permanent support, timber should be well seasoned and treated with preservative. It is easily framed on the job and quickly erected without use of special tools or equipment. For temporary support, in local stretches of bad ground while advancing the heading timbers are readily cut and framed to suit requirements.
Timber sets comprises several timbers forming a framework across the tunnel section. The commonest form for narrow tunnels is the 3-piece set, consisting of a cap (crossbar or header) supported on two posts. The batter of the posts is 1 to 1.5in per ft, which is usually sufficient to prevent the bottoms of the posts. From pushing inward unless side pressure is excessive and the bottom soft. Posts are usually of hardwood, round, with small end 5-in minimum diameter. The minimum thickness of the cap is usually 5-in with width from 6 to 8 in. Lagging, usually 2 in thick, may or may not be set on the sides and top.
In swelling ground the timber set usually has :batter blocks” to prevent the displacement of the posts; where the bottom tends to heave, an inverted arch set may be used. The back (or roof) of the tunnel often stands better if arched, especially in wide tunnels. Where only the back requires support and the walls are strong, posts may be omitted and the arched timbers set in hitches out at the break-line of the arch. Size of timbers and interval between sets depend upon size of tunnel and pressures to be withstood. Swelling ground should not be close-lagged, but spaces left between adjacent pieces of lagging, through which pressure can be relieved.
Routine and speed of timbering depend largely on how close the timbering must be kept behind the face. If each round of advance must be supported at once, timbering becomes a part of the driving cycle. The first step after blasting is to scale the back; and , in loose ground, to hold the back ahead of the last set by forepoling, sliding booms or similar means, to protect men while mucking. After the round is mucked, the new set is erected, blocked in place and lagged if necessary, and the drills are set up for the new round. timbers can be standardized and a regular routine followed. Speed is gained by baving all materials and supplies at the face before work begins; timber for a compete set, blocks, wedges, lagging and tools, should be brought in with the crew. Where the timbering lags a considerable distance behind the face, a special timber crew is usually employed. With suitable scaffolding, work can proceed without interfering with driving operations. A movable scaffold, with a working deck several sets long and high enough to allow the tunnel cars to pass under it, may be advantageous.
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