【正文】 每茬炮的深度取決于整個(gè)掘進(jìn)循環(huán)和巷道的斷面尺寸。采用直眼掏槽，炮眼 組的深度可比斜眼掏槽大一些，因?yàn)槊坎缗诘倪M(jìn)度增加了，證明其更為經(jīng)濟(jì)。在較大斷面巷道中，斜角眼掏槽比直眼掏槽優(yōu)越，因?yàn)榕谘蹟?shù)目少掏，每掘進(jìn)一英尺巷道所需炸藥量少。 (3)安裝支架，支護(hù)剛掘出的巷道，敷設(shè)接長軌道、風(fēng)管和電纜，為下個(gè)循環(huán)作好準(zhǔn)備工作。炮眼均填以炮泥，以防止 (在延期爆破中 )光爆炮眼爆轟時(shí)將藥包帶出。因?yàn)殂@大直徑炮眼容易準(zhǔn)直，所以緩沖爆破法采用大直徑炮眼時(shí)一次爆破深度以達(dá)一百英尺。預(yù)裂炮眼比鄰近主炮眼先起爆，以形成有利于主炮眼爆破的裂面。輪廓線眼的最大深度大約為 30英尺。 奈特羅諾貝爾 (硝化諾貝爾 )公司曾創(chuàng)造一項(xiàng)專用泵送炸藥的工藝，它包括一臺直接把炸藥泵入炮眼的槽車。半自動(dòng)裝藥器的裝藥能力比普通的裝藥器高得多。裝藥時(shí)雷管必須送到炮眼中的準(zhǔn)確位置。最古老的裝藥方法是用炮棍裝藥，這種方法至今仍廣泛使用。巖石溫度的增加使巖石的強(qiáng)度降低。 裝藥的方法決定破碎某種已知巖石時(shí)上述三方面的相對比例和所消耗的能量。 and advancing the ralls. ventilation arrangements, and power supplies ready for the next cycle of operations. The basic principle of tunnel blasting ,in its simplest term, is to loosen a volume of the virgin rock in such a way that when it is removed the line of the tunnel has advance in the correct direction with as nearly as possible the correct crosssection. The dilling pattern in which the holes to receive the explosives are drilled into the working face is designed so that :the holes are easy to drill。 the minimurd total quantity of explosive is required 。無約束時(shí)巖石拉伸破壞所消耗的能量最少，在破巖過程中如巖石受到較高的壓應(yīng)力場的約束時(shí)，破巖能量需要有所增加。但這種效應(yīng)非常小，因?yàn)椴傻V的時(shí)候周圍溫度變化小。在過去二十年中，壓風(fēng)裝藥器已被采用，這些裝藥器既提高裝藥效率，同時(shí)又改進(jìn)裝藥密度，因此炮眼的利用率較高。 壓風(fēng)裝藥器在瑞典已使用了大約二十年。 散裝炸藥一般為硝銨炸藥 (銨油炸藥 )，需要專用裝藥器。向大直徑炮眼裝藥時(shí)其裝藥能力極高。由于輪廓線鉆眼法的最后一排眼不爆破，因而對巖壁的破壞最輕。預(yù)裂爆破中在鄰近主炮眼爆破之前很難判斷其效果。但緩沖爆破在井下很少使用。光面爆破減少巷道的超挖，增強(qiáng)圍巖穩(wěn)定性并減少支護(hù)量。 簡而言之，巖巷爆破的基本原則是，把巖體上一部分巖石破碎下來，當(dāng)裝走爆落的巖石后，巷道按正確的方向前進(jìn)，其斷面盡可能地接近設(shè) 計(jì)斷面。其缺點(diǎn)是 “ v” 形掏槽有可能拋出大塊巖塊。直眼掏槽的槽眼要平行，眼距要適當(dāng)，其深度要比其他炮眼深 1／ 2~1英尺。一般 規(guī)律是，一茬炮的深度不要超過巷道最小斷面尺寸太多。一般來說，炮眼引爆的順序應(yīng)使每個(gè)炮眼或一組炮眼隨前一響炮眼所形成的自由面爆破。 大直徑掏槽直眼在大斷面巷道中可為良好的擴(kuò)槽創(chuàng)造條件。這兩種掏槽方式可以聯(lián)合組成其他各種掏槽方式。 (2)裝巖 (將爆破的巖堆裝運(yùn)出去 )?？椎籽b藥量稍多一些。這種方法的裝藥方式與預(yù)裂爆破法相似。預(yù)裂爆破的深度受炮眼排列的限制，最大深度約為 50英尺。靠近輪廓線鉆眼的炮眼，起裝藥量及眼距均比其他炮眼小。最大為 30千歐米。裝藥時(shí)裝藥欽管中的風(fēng)壓不變。用炮棍裝藥時(shí)，若想裝填得好，那么一次只能裝填并搗實(shí)一個(gè)藥卷。 2 炮眼裝藥方法 炮眼裝藥的方式可根據(jù)所采用的炸藥是藥卷或散裝而有所不同。雖然孔隙流體的化學(xué)作用對巖石的強(qiáng)度有影響，僅和約束力作用比較，除少數(shù)幾種巖石外，一般都比較小。破巖的能量在以下三個(gè)主要機(jī)理內(nèi)被消耗掉： (1)形成新的表面 (破巖能量 )， (2)摩擦 (塑性 )， (3)傳播彈性波能。charging them with explosives and blasting. (2) Removing the resulting muck pile. (3) Inserting the tunnel linings into the newly excaved area。and the periphery of the space left after the blast conforms as nearly as possible to the required tunnel section. A blast round consists of cut ,relief, breast and trim holes . The cut portion is the most important . The objective of the cut is to provide a free face to which the remainder of the round may break. The two general types of cuts are the angled cut and the burn .These can be used in binations to form various other cuts .Angled cuts are more advantageous than burn in wide headings ,due to the fewer boles and less explosive required per foot .A disadvangtage is the possibility of large pieces of rock being thrown from the “V”. The wedge or Vcut consists of two holes angled to meet or nearly meet at the bottom . The cut can consist of one or several Vs, either verticao or horizontal .For deeper rounds or hardbreaking rock ,double Vs can be used .The smaller is called the baby cut . It is useful in small burn holes provide excellent relief in big headings .Burn cuts permit deeper rounds than angled cuts and , due to the increased advance per round ,may prove more economical .In burn cuts ,the holes must be drilled parallel , with proper spacing ,and : 1 ft deeper than the remainder