按照施工工艺的不同,喷射混凝土可分为干法和湿法喷射两种。由于干法喷射具有能输送较远的距离,工作风压低,喷头脉冲小,工艺和设备简单,对渗水岩面适应性好,混凝土抗压强度高以及干拌料可以存放较长的时间等特点,所以它在喷射施工中仍占统治地位,我国绝大多数单位的喷射混凝土施工都用干法喷射。但干法喷射的缺点是回弹率高,粉尘大。粉尘大污染作业环境,严重危害操作人员身体健康, In accordance with the different construction techniques, shotcrete can be divided into two kinds of dry and wet jet. Because dry jet has the ability to transport a long distance, low working pressure, nozzle pulse, simple process and equipment, good adaptability to seepage water, high compressive strength of concrete and dry spices can be stored for a long time and so on , So it still occupies the dominant position in the jetting construction. The spray concrete construction of most units in our country use the dry jetting method. But the disadvantage of dry jet is the high rebound rate, dust big. Dust pollution in the operating environment, a serious endanger the health of operators,