Micro-hole precision anchor breaks the deadlock: Small DTH Drilling Rig enables precise ground anchoring
Industry pain points and solutions
In projects such as building foundation pit support and slope reinforcement, traditional anchoring equipment often faces three major difficulties: first, limited operation in narrow spaces; second, insufficient drilling accuracy leads to dispersed anchoring force; third, weak adaptability to complex geology. Take a subway project as an example. Because the foundation pit is close to the existing line, the traditional drilling rig cannot operate close to the red line due to its large size, which eventually leads to a 30% overspending on support costs.
In response to the above pain points, we launched the Small DTH drilling rig solution. The equipment adopts a modular design, with a main machine weight of only 5.4 tons, which can easily enter a 3-meter wide working surface; equipped with a digital guidance system, the drilling deviation is controlled within ±2cm; with the recyclable anchor cable technology, the anchoring section length is digitally traced in the Shenzhen Meiyuan project, and the cost of a single anchor is reduced by 40%.
Equipment performance and technological innovation
This solution integrates three core equipments:
PCR-DTH-Ⅱ split drilling rig: The drilling diameter is 40-89mm, the depth is up to 15 meters, and it is equipped with a 25m³/min Air Compressor. It has set a record of 32 meters of daily footage in the sandstone formation of the Wuhan Sunac project.
Excavator modified drilling rig: Using the existing excavator power system, the drilling and digging are integrated through quick-change joints, which reduces the equipment transportation time by 60% in a commercial complex project in Hangzhou.
Drilling And Splitting Machine: It adopts a high-frequency impact (17kW power head) and static splitting combined process to increase the anchoring force in granite formation by 2.3 times.
The equipment adopts a pressure-type anchor cable structure, and the steel strand anti-corrosion level exceeds the national standard level 1. With the digital ring monitoring system, the anchoring force-time curve can be obtained in real time. The application of Shenzhen Vanke project shows that this solution improves the accuracy of anchor cable locking value from 0.6-1.1 times of the empirical value to the range of ±5%.
Practical application and benefit analysis
In the Wuhan World City project, the pile anchor solution was used to replace the traditional pile support process:
The cost was reduced by 22% (23 million → 18 million)
The construction period was shortened by 3 months
The deformation of the foundation pit was controlled within 15mm
Equipment features:
Laser coding anchor cable realizes length traceability
Hot-melt recyclable anchor cable solves the problem of occupation outside the red line
Digital anchor technology accumulates engineering data and forms a design parameter library
Construction tips:
Soft soil layers use a decentralized process and set 3-5 anchor units
The best time for secondary grouting is 2 hours after the first grouting
Drilling tools are checked every shift, and the spiral groove is replaced immediately if it is blocked by more than 30%
This solution has been verified in more than 20 key projects, with an average increase in construction efficiency of 35% and a reduction in material costs of 18%. Through technological innovation and process optimization, Small DTH Drilling Rigs are redefining the standard of precise anchoring. 
Jiangsu Aneng Drilling Equipment Technology Co., Ltd.
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