澜沧铅矿凝灰岩巷道变形失稳规律及支护方案改进研究

【作者】 田昌进；

【导师】 侯克鹏；

【作者基本信息】 昆明理工大学 ， 安全技术及工程， 2009， 硕士

【摘要】 软岩巷道支护一直是困扰矿山安全生产的重大问题之一。多年来,澜沧铅矿在进行生产的过程中一直遇到凝灰岩巷道支护的问题,由于该处凝灰岩遇水极易膨胀风化,更有甚者还会泥化,致使巷道极不稳定,常出现冒顶、两帮内挤、底鼓,甚至全断面变形破坏,其中底鼓最为严重；在对该矿山巷道进行治理的过程中,采用了混凝土反拱、木架厢等支护方案,但在支护后短时间内又发生破坏,造成不断地扩底、扩帮并进行返修的问题,严重破坏了巷道的稳定性,影响了该矿山的正常生产,造成巨大的经济损失。本文针对该巷道破坏的具体情况,以1700中段为研究对象进行如下相关研究：(1)凝灰岩的室内实验研究。通过对凝灰岩进行微观实验、含水率实验、崩解实验、膨胀实验和点荷载实验,从凝灰岩的水理性和力学特性来分析凝灰岩的变形破坏规律,得出该处凝灰岩中含有大量的粘土矿物,其中主要以高岭石为主,含有一定量的蒙脱石,该处凝灰岩的强度较低,属于中膨胀性软岩,在不遇水情况下和干燥环境中,很少发生膨胀、崩解、风化；但一旦遇水,其耐崩解能力大幅降低,膨胀性能大幅提升,膨胀速度加快,风化程度较严重,加之气候、温度的干湿循环、冷热循环影响,更加快了凝灰岩的破坏速度。从实验当中可以看出水是造成巷道破坏的主要原因,同时地层压力的影响也起到一定的促进作用,由此提出要治理巷道破坏,首先要防水的思路。(2)灰土改良的相关实验研究。通过石灰改良凝灰岩的方案,做灰土改良在不同掺灰率、不同含水率下的膨胀实验,得出当含水率在12%～15%,掺灰量在15%时,其改良效果较好。同时通过物相分析改良后的岩样,从微观角度分析得出石灰改良凝灰岩后其塑限增强,渗透性降低,强度提高的原因,使灰土改良的方案得到了有力支撑。本文以实际工程为研究对象,采用锚喷网的支护方法对顶板及两帮进行支护,同时采用灰土改良的治理方案对底鼓进行治理。该方案施工简单,取料方便,延长了巷道的使用时间,返修快捷,为企业带来了较为显著的经济效益和社会效益,同时对类似工程提供了具有参考价值的支护方案和研究思路。更多还原

【Abstract】 Soft rock tunnel supporting is one of the greatest problems in mining security production. The problem of tuff tunnel supporting has always been disturbing LanCang Lead Mine’s security production for many years. The tunnel in this mine has become very instability because the tuff here can easily get expansion and weathering, sometimes even get mudding when it is influented water. The serious results of this phenomena are roof fall, squeeze in two sides, floor heave and the broken of its full section. During them, the floor heave is the most serious one. In the process of governing this mine, the methods of concrete invert arch and wooden stand had been taken. But problems always occurred not long after that:the constant base enlarging, slope expansion and too many times of rework. All these had seriously affected the normal production of this mine and brought great economical loses.The 1700 level was taken as an example for all the researches done in this essay according to the details of this mine’s broken situation.(1) Laboratory experiments of tuff. Many experiments were done firstly, like the micro-experiment, the water ratio experiment, the disintegration experiment, the swelling experiment, and the point load experiment, then I seriously analysised the tuff s deformation-failure law from its hydrological properties and mechanical properties. Finally I got several results:LangCang Mine’s tuff contains manyclay minerals,most of which is kaolinite, and it also contains a certain rate of montmorillonite. The tuff here has very low substantial stebility, so it is a kind of medium dilatability soft rock. In the water and dry situation, it merely expand, disintegrate and weather;but when it is influented water, it’s expansion ability would be greatly increased. It can expand in a very high speed and come up to a high weathering degree. In addition of the influence of the tempreture’s dry-wet cycle and thermocycling, its broken process can be greatly accelerated. So from this experiment, I finally came to the conclusion that water is the main reason which brings the tunnel’s broken, and formation pressure has also affected this in a kind of degree. So the clue of waterproof should be carried out firstly in tunnel protecting.(2) Relevant research about lime-stabilized soil.Throuth the experiment of lime’s expansion in different lime ratio and water content according to the idea of lime improve tuff, I got the conclusion that it has a better improving result when its water content is 12%～15% and mix lime dosages is 15%. Then after anglicizing the rock samples by phase analysis, I got the reason for the enhance of the lime improved tuff s plastic limit, the depression of its penetrability and the improving of its intensity, which powerfully supported the idea of soil amelioration.Practical engineering had been taken as the research objects in this papper. The support method for the roof and the tunnel’s sides is bolting and shotcrete wire, and the treatment scheme for the floor heave is soil amelioration. This treatment scheme has many advantages such as simple construction, reclamation convenience, can prolong the tunnel’s using time and rapid rework. So it brings a magnificent economic benefit and social benefit for the enterprises. What’s more, it provides a reference valued support method and research thought for the similar engineerings.更多还原