Original title: Picture and text | Why is the two-arm rock drilling jumbo favored? What is a drilling jumbo? What is the rock drilling jumbo used for? Rock drilling jumbo is a kind of rock drilling equipment for tunnel and underground engineering construction by drilling and blasting method. It can move and support multiple rock drills for simultaneous drilling operations. Drill jumbo can be divided into drift driving drill jumbo, mining drill jumbo, bolt drill jumbo and drill jumbos for open-pit mining, and can be divided into single-arm, double-arm and multi-arm drill jumbos according to the number of rock drills erected. According to historical records, the earliest rock drilling technology was in the Warring States Period, when Li Bing built Dujiangyan with the method of "burning water". Before 1900, the ancients used this method to dig the world's first artificial tunnel through the mountain, which is 16 meters long, 4 meters high and 4 meters wide. The method of fire water shock is to use the principle of rock expansion and contraction, and then quickly pour water after fire, so that the rock will crack, or even become like cutting tofu. With the development of metallurgical technology, people use chisels or steel drills to knock the rock bit by bit to crush it, thus digging a hole in the rock, and "hand hammer drilling" once became the mainstream. After the Industrial Revolution, human beings have mastered the power, and the demand for rock drilling has greatly increased, and various rock drilling tools have emerged as the times require. In 1813, the first impact rock drill powered by steam came out, but because of the high temperature of steam, it was not convenient to use, and the long pipeline had the problem of cooling, it was quickly replaced by the rock drill powered by compressed air, and successfully applied in the Alpine Seni Peak Tunnel. The pneumatic rock drill formally entered the historical stage and became the core force of rock drilling construction. Expand the full text Although the pneumatic rock drill has many advantages, with the increase of the hole depth, it is found that the drill rod joint will lose a lot of impact energy, and the working environment is poor. With the development of hydraulic technology, hydraulic rock drills began to be used in drilling operations, and rock drilling jumbos with higher mechanical degree gradually replaced manual drilling. Its appearance greatly improves the drilling speed, correspondingly improves the overall construction progress, improves the working environment, and greatly reduces the labor intensity of workers. Since the 1980s, rock drilling jumbos have been introduced into some long tunnels in China, but due to the low quality of construction personnel, inadequate construction management level, unreasonable mechanical matching and other factors, since the 1990s, manual hand-held air gun with simple bench drilling method has been widely used again. In today's domestic tunnel field, some construction units spend tens of millions of yuan to purchase foreign drilling equipment (among which three-arm drilling jumbo is the mainstream) in response to the requirements of superior leaders for "full mechanization reform of construction". However, after field application, the advantages of mechanized equipment have not been reflected, but in most projects have formed a situation of "not easy to use, but a pity to abandon".. It is difficult to implement the three-arm rock drilling jumbo in China. The main reasons are as follows: 1. The three-arm scheme is expensive. ? Although labor costs can be saved in the construction process, the overall cost performance improvement is still not significant. 2. The imported rock drilling jumbo has a low degree of localization. ? It is difficult to train professional operators, so that the drilling jumbo can not give full play to its effectiveness. 3. Imported rock drilling jumbo is difficult to supply spare parts in China , resulting in inconvenient maintenance; at the same time, it has higher requirements for the construction environment, and the current domestic construction environment is difficult to meet the conditions. 4. At the time of system bolting ? Due to the large size of the three-arm drilling jumbo,DHD Drill bit, it is easy to block the traffic and inconvenient for construction, resulting in low utilization rate of equipment. So in the process of tunnel drilling, what kind of equipment does the construction unit need to choose in order to give consideration to both "mechanized reform" and "construction benefit"? I believe you already have the answer. Return to Sohu to see more Responsible Editor:. wt-dthtools.com