TBM Disc Cutter Inspection and management

1. Optimize TBM disc cutter configuration

Geological factors are the key factors in determining TBM cutter wear. In construction, it is necessary to select a reasonable cutter configuration and a more suitable maintenance process according to the material composition of the rock, rock strength, rock hardness, and the development of the structural surface. Reasonable cutter configuration is a prerequisite for the smooth tunneling of TBM.

The large-diameter TBM cutter head has a larger layout space, and a larger-sized TBM roller cutter can be selected (such as 18 Inch Disc Cutter, 19 Inch Disc Cutter, 20 Inch Disc Cutter).

Because the large-sized disc roller cutter has stronger wear resistance than the small-sized one under the same conditions, and the large-sized disc roller cutter can withstand greater impact force, it can greatly alleviate the tool damage caused by TBM due to high thrust and high torque, and can effectively reduce the frequency of cutter replacement and improve the utilization rate of TBM equipment.

Under different geological conditions, the surrounding rock produces different torque forces on the TBM roller cutter, so the corresponding cutter should be reasonably configured according to the surrounding rock conditions when the TBM is excavating.

Generally speaking, soft rock is equipped with lower-torque cutters, and hard rock is equipped with larger-torque cutterss. With reasonable operating parameters during construction, the performance of the TBM roller cutter can be maximized.

The quality, performance and parameters of the disc cutter ring, hub and other components are an organic whole. The cutter ring, hub, shaft, etc. directly bear the external force of the surrounding rock.

The internal structure of the disc roller cutter, such as bearings, seals, lubricating grease, etc., are the keys to ensuring the normal rotation of the TBM roller cutter when it is working. Therefore, during the assembly of the disc roller cutter, the quality of each component should be strictly controlled and the assembly process should be refined to ensure the performance of the TBM roller cutter.

2. Daily inspection of TBM roller cutters

TBM cutters must be cleaned, inspected and measured every day. The inspection items include the degree of wear of the disc cutters and the gauge scrapers, and the tightness and integrity of the cutter mounting bolts.

If the cutter mounting bolts are loose or damaged, they should be tightened or replaced in time. The worn and damaged disc cutter and side scraper should be properly dealt with in time to ensure their rock breaking and slag removal capabilities and to prevent wear on the cutter head.

When excavating in hard rock or special geological sections, the inspection frequency of the TBM cutters should be appropriately increased according to the actual construction, and if necessary, the machine should be stopped at any time for inspection, because under the condition of high thrust and high torque, the excavation distance of several tens of centimeters may cause serious consequences.

During construction, it is necessary to comprehensively judge the cutter wear condition according to the excavation parameters, slag samples and slag discharge conditions. Because the TBM will generate different thrusts and torque under different surrounding rock conditions, the operator needs to carefully summarize the experience and find out the rules.

According to the analysis of surrounding rock, tunneling parameters and slag condition, the wear condition of the cutter is judged, and TBM should stop in time to check the tool when it is found abnormal.

If possible, a magnet can be installed above the slag belt, which can effectively absorb the iron filings or installation accessories generated by cutter wear. We can analyze and master the wear of TBM cutters at the first time according to the situation of the adsorbate.