The construction challenges of Class V surrounding rock in tunnel projects have long hindered the development of the industry. The pain points of traditional construction methods, such as low efficiency, high cost, and high safety risks, urgently need to be addressed.

Traditional tunnel soft rock construction faces three prominent dilemmas. When facing Class V hard rock, hydraulic breakers have small single volume, fast wear of vulnerable parts, and frequent replacement of accessories is likely to delay the construction period; although shield machines are suitable for complex geology, the purchase cost of a single unit exceeds 10 million yuan, which has strict requirements on the construction site and supporting facilities, making it difficult for small and medium-sized projects to bear; due to the tightening of environmental protection and safety policies, explosive blasting is also prone to cause surrounding rock collapse in complex geological areas such as western mountainous areas, resulting in greatly limited application scenarios.

To address the industry pain points, Chang'an chuanshanjia has developed a tunnel excavation hook arm based on exclusive patented technology, which accurately meets the needs of tunnel construction in complex geology and has prominent core advantages.
Its arm length is optimally designed to rotate flexibly in narrow tunnels, completely solving the problem that standard arms "cannot rotate and collide with the top", and is suitable for various tunnel sections; it is equipped with a bidirectional cutter tooth structure to fully cover the working surface and improve construction continuity; it is cut and formed from a single block of high-strength manganese steel, which can withstand various harsh working conditions and greatly reduce equipment loss and maintenance costs; the operation disturbance is small, there is no risk of flying rocks, and safety hazards such as collapse are avoided.

The tunnel arm product has been applied in tunnel projects in many places such as Leshan City, Sichuan Province, Jiuquan City, Gansu Province, Longnan City, Gansu Province, and Shangri-La, Yunnan Province, and has received wide recognition from construction parties and regulatory authorities.

In the water diversion channel project of China Railway 18th Bureau in Shizhong District, Leshan City, Sichuan Province, the combination of Sany SY485 excavator and Chang'an chuanshanjia tunnel hook arm, relying on exclusive patented technology, achieved efficient, low-cost and safe controllable hard rock construction. The equipment working range covers the full-section construction of the top, front and lower parts, the comprehensive construction cost is reduced by 22%, the project payback period is shortened to 10 months, and there is no blasting operation throughout the process, achieving zero safety accidents.
(Construction site of the water diversion channel project of China Railway 18th Bureau in Shizhong District, Leshan City, Sichuan Province)

In a tunnel project in Jiuquan, Gansu Province, the geological structure is complex, the proportion of Class V surrounding rock is extremely high, and there are construction risks such as large deformation of soft rock and water gushing. Traditional hydraulic breaker operation is inefficient and prone to frequent failures, which seriously affects the construction period. After multiple investigations and comparisons, the project party took the lead in purchasing one Sany SY485 equipped with Chang'an chuanshanjia tunnel hook arm for construction. The user experience exceeded expectations, and another unit was ordered two months later to continuously expand the construction investment.
(Tunnel arm forward excavation construction)
(Tunnel arm upward excavation construction)
As the only mass-produced tunnel hook arm product on the market currently, the successful application of Chang'an chuanshanjia tunnel hook arm marks that tunnel hard rock construction has entered a new era of "high efficiency, low cost and safe controllability". Its exclusive patented technology and mature construction scheme can adapt to the tunnel construction needs of different geology and different sections, empower more tunnel projects to break through difficulties, and continuously promote the tunnel construction industry to develop in a more efficient, environmentally friendly and sustainable direction.