Starting from the Wenxian section of the Wujiu Expressway (Wudu to Jiuzhaigou), the road climbs steeply through sharp bends. Amid high mountains and deep valleys, the portals of two parallel tunnels come into view—this is the 12.2 km Gaoloushan Extra-Long Tunnel, currently the third-longest highway tunnel in Gansu Province.

Approaching the tunnel, a rhythmic "rat-tat-tat" sound rings out as a machine extends three "arms" simultaneously, drilling into the rock face three to four meters high. Speaking of this XCMG three-boom rock drilling jumbo, the operator nearby is full of praise: "This big guy swings its arms and does in a day what would take several days by hand—and most importantly, it keeps us safe."

Three-Boom "Iron Man" Battles the Extra-Long Tunnel

The Gaoloushan Extra-Long Tunnel is a controlling project of the Wujiu Expressway, with a maximum burial depth of 1,680 meters. The surrounding rock changes every few dozen meters, and rockbursts and karst phenomena occur frequently. The tunnel crosses fractured rock zones multiple times and combines multiple complex technical challenges, including rockbursts, sudden water inrushes, dissolution crystallization, karst, and high ground temperatures.

The XCMG TZ3A three-boom rock drilling jumbo is specifically responsible for excavating the main tunnel of the Gaoloushan double-tube separated tunnel. To ensure uninterrupted progress of the first construction process, XCMG Foundation formed a five-person construction-method technical team to provide on-site support, scientifically plan the construction scheme, and use the three-boom rock drilling jumbo for full-face mechanized drilling and blasting.

During construction, drilling at the tunnel face and explosive charging are performed by the XCMG three-boom rock drilling jumbo instead of manual labor, making mechanized construction more time-efficient.
The XCMG three-boom rock drilling jumbo keeps overbreak and underbreak within the qualified range and completes the excavation task with guaranteed quality and quantity. As of November, the right tube at the exit of the Gaoloushan Tunnel on the Wujiu Expressway has been successfully holed through.

Single-Boom Operations Set a Benchmark for Promotion

In Chongqing, at the 7.5 km Wushan material transport tunnel, four XCMG CYTJ45 single-boom rock drilling jumbos participated in mechanized construction of three tunnels, with a single machine achieving a monthly advance of 309 m, making it a high-quality benchmark project promoted by the owner and the local government.

This project is a key application project approved by the Wushan government. Crushed stone from quarries in the mountainous area will be transported through a small tunnel and a conveyor belt directly to cargo ships on the Yangtze River; this straight-line transport greatly saves manpower and material costs.

Since the XCMG CYTJ45 single-boom rock drilling jumbos entered the site, they have operated around the clock with machines running while people rest, assisting the construction unit in overcoming extreme construction challenges such as fault fracture zones and reverse-slope drainage. With utility model patents and multiple construction-method verification results, they have boosted high-quality tunnel drilling.
The era of chipping holes and blasting bit by bit with sledgehammers and steel chisels has passed. Today's China, with its strong national strength and powerful equipment capabilities, no longer has to rely solely on winding mountain roads when facing towering mountains. With modern machinery and equipment, the XCMG mining and tunneling sector adopts new drill-and-blast construction technologies to carve a smooth path through the mountain belly, achieving passage through mountains and across ravines.