岩石开挖的主要方法有爆破破岩法和机械破岩法，这两种方法均存在一定缺点，前者对原岩的扰动大、开挖硐室支护困难，后者一次投资高、刀具寿命短、成本高等，因此找到一种高效的岩石破碎方法是广大工程技术人员所期盼的。已有的研究表明，利用微波照射可以降低岩石强度，有助于提高机械破岩的效率，因此“微波+机械”有望成为岩石开挖的高效方法,并将有助于实现破碎过程中低噪音及低粉尘等优点。 本文以研究微波照射下岩石强度的弱化为目的，通过改变微波功率、微波照射时间、岩石种类等多种因素，研究微波照射引起岩石强度弱化的规律，并通过数值模拟和实际的微波照射试验对岩石在微波照射下的强度弱化原因进行分析。具体研究内容及取得成果如下： （1）结合微波加热原理探讨微波照射造成岩石损伤的机理。微波照射引起岩石温度升高，使得岩石内部应力增大、分布发生变化进而影响岩石强度，微波照射引起岩石强度弱化与微波功率、微波照射时间、岩石类型（构造、矿物组成）有关。 （2）利用数值模拟软件建立岩石试件内部裂隙和矿物颗粒的仿真模型，得到微波照射下裂隙内部及矿物颗粒周围的应力变化情况。其中，岩石内部裂隙在微波照射下的应力分布为：裂隙尖端出现明显应力集中，随功率增大、照射时间增长应力集中越明显。 （3）在微波照射岩石的试验过程中，通过改变照射参数得到不同情况下不同岩石强度损伤情况：功率越大、照射时间越长岩石强度损伤越明显；不同岩石在相同的试验条件下强度损伤不同；岩性相同构造不同的岩石试件在相同的试验条件下损伤也不同。不同岩石对微波照射因素敏感性不同，如：花岗岩和石灰岩对照射时间改变较为敏感，陕北地区砂岩对微波功率改变较敏感。

The main method of rock excavation has blasting and mechanical, two methods have some shortcomings, the former large disturbance of the original rock, difficulties chamber support, the latter high the first investment and short tool life, high cost and so on,so the engineers hope to find an efficient rock breaking method. Researches show that, The rock strength can greatly reduce by microwave irradiate, to help to improve the efficiency of mechanical crushing rocks, so "Microwave and Mechanical" is expected to become effective method of rock crushing, helping achieve low noise and low dust in rock crushing process. The purpose of this paper is to weaken the strength of the rock under microwave irradiation, by changing the microwave power, irradiation time, types of rocks and other factors, study the law of rock strength weakening cause microwave radiation, analyzing of the reasons for the change rock strength under microwave irradiation by performing numerical simulation and actual microwave irradiation test. Specific research and the results achieved are as follows: (1) Discussion of microwave irradiation damage on the principles of rock strength combined knowledge of microwave. Rock temperatures cause microwave radiation, making the internal stress of rock increases, stress distribution change and affect rock strength, rock strength weakening cause by microwave radiation power, microwave irradiation time, rock types, (structure and mineral composition). (2) By using numerical simulation software to establish internal fissure and mineral particle simulation model of rock specimen, get the situation under microwave irradiation stress cracks around the internal and mineral particles. Rock internal stress distribution of cracks under microwave irradiation, crack tip appears obvious stress concentration, the stress concentration, the more obvious with the increase of power and irradiation time. (3) In the microwave irradiation test, get various rock strength injury under different circumstances by changing the irradiation factor:The greater the power, the longer time, the more obvious damage to the rock strength, the different sensitivity of rocks in microwave irradiation of different factors, for example, Granite and Limestone are more sensitive to changes in irradiation time, the Sandstone of Northern Shaanxi sensitive to changes in the microwave power