I. Core Hub: Functions and Types of Main Development Roadways

Within the entire underground mining system, the main development roadways rightfully serve as the core hub, playing a decisive role in the overall production and operation of the mine. These roadways are categorized into three major types: shafts, drifts, and chambers—each type further encompassing multiple specific engineering forms, all of which fulfill unique and critical functions.

(1) Shaft-type —— Vertical / Inclined Transport Mainways

As a critical passage connecting the surface to underground ore bodies, shafts can be further classified into various types—such as main level adits, hoisting shafts, main rampways, and blind vertical or inclined shafts—depending on their dip angles and intended purposes. Together, these structures form the primary transportation network for both vertical and inclined movements beneath the mine.

1. Main Level Adit

The main decline is a horizontal roadway that connects directly to the surface and has a long axis nearly parallel to the horizontal plane, playing an extremely critical role in mine operations. Its direct connection to the ground makes it the ideal choice for handling the mine’s primary transportation tasks. After materials such as coal are extracted from the underground working face, they can be conveyed via equipment like belt conveyors—leveraging the main decline’s gentle horizontal slope—to achieve gravity-assisted, self-flowing transport, eliminating the need for additional lifting equipment. This significantly streamlines the transportation process, reduces both the number of handling steps and the equipment required, effectively lowers transportation costs, and boosts overall efficiency.

Take a mine in Southwest China as an example: This mine employs the main adit development method, with the main adit stretching over 2,000 meters. Coal extracted from the underground mining face is transported via scraper conveyors to belt conveyors installed within the main adit, and then directly conveyed to the coal preparation plant at ground level. Compared to other development methods, this transportation approach significantly reduces coal-handling time, enabling the mine to move hundreds of tons more coal daily while cutting transportation costs by approximately 30%. Meanwhile, the main adit also enjoys a natural advantage in drainage—its outward slope remains steady at 3 to 5 degrees, allowing underground water to flow naturally out of the mine without the need for complex drainage chambers or equipment inside the adit. This not only minimizes the volume of underground roadway construction and lowers drainage expenses but also enhances the mine's overall safety against potential water-related hazards.

2. Enhance the wellbore

The hoisting shaft is a critical component of the mine hoisting system, primarily comprising vertical shafts and inclined shafts, which differ in depth and dip angle, making them suitable for various orebody conditions and mining requirements.

Shaft: As vertical shafts driven downward, shafts occupy a central role in the development of deep mineral deposits. Depending on the type of hoisting container and their specific applications, they can be further classified into skip shafts, cage shafts, and combined shafts. Skip shafts are specifically designed for ore hoisting, with skips serving as their lifting containers. They feature large lifting capacities and high efficiency, making them ideal for large-scale mining operations. Cage shafts, on the other hand, primarily facilitate the transportation of personnel, equipment, and materials, while also handling tasks such as waste rock removal. The design of cages allows for convenient loading, unloading, and easy access for both people and cargo, thereby supporting the diverse needs of daily mine production activities. Combined shafts, meanwhile, integrate the functions of both skips and cages, capable of hoisting ore as well as transporting personnel and equipment. These are typically used in smaller mines or in the expansion and deepening projects of older mines, where complex production requirements must be met. When constructing shafts, it is essential to equip them with well-designed bottom car yards and hoisting equipment chambers. The bottom car yard serves as a vital hub connecting the shaft to underground roadways, managing tasks such as mine car scheduling, temporary ore storage, and transfer operations. Meanwhile, the hoisting equipment chamber houses critical machinery like hoists and winches, ensuring safe and efficient operation of the hoisting system.

Inclined shaft: The shaft is excavated downward at a specific inclination angle, typically ranging between 15° and 45°. Inclined shafts are also classified—based on the hoisting equipment and their intended use—into skip-type inclined shafts, trolley-type inclined shafts, and belt conveyor shafts. Skip-type inclined shafts are primarily used for transporting large volumes of ore, lifting underground minerals to the surface via skips, making them ideal for mines with high production capacities. Trolley-type inclined shafts, on the other hand, are commonly employed in medium- and small-scale mines for auxiliary transportation, utilizing mine car sets to move ore, waste rock, personnel, and equipment materials. While these shafts offer greater transport flexibility, their capacity remains relatively limited compared to skip-type systems. Belt conveyor shafts, meanwhile, rely on belt conveyors as their primary transportation system, enabling continuous material handling. They boast significant advantages such as high transport capacity, exceptional efficiency, and advanced automation levels, particularly well-suited for long-distance, high-volume ore transportation. Compared to vertical shafts, inclined shafts generally involve lower construction costs and faster excavation rates, giving them a clear advantage when mining moderately inclined ore bodies. For instance, a certain metal mine adopted an inclined shaft development approach, with a shaft length of 1,500 meters and an inclination angle of 25°. Equipped with a belt conveyor system, this inclined shaft efficiently transports thousands of tons of ore to the surface each day, fully meeting the mine's production needs. At the same time, the construction cost was approximately 20% lower than that of a corresponding vertical shaft.

3. Main Inclined Ramp

The main ramp is a dedicated passage for trackless equipment to move underground, with a typical gradient ranging from 8% to 15%, tailored to meet the operational and transportation needs of vehicles. Depending on their service scope and function, ramps can be classified into main ramps and mining area ramps. The main ramp connects the surface with each stage underground, serving as the primary route for trackless equipment entering and exiting the mine as well as for transporting ore. It enables large trackless vehicles like trucks and loaders to directly reach the working face, thereby achieving mechanized and highly efficient underground transportation. In contrast, the mining area ramp is primarily designed to support the extraction of specific ore bodies, providing a dedicated pathway for trackless equipment within the mining area and significantly enhancing transportation efficiency inside the zone.

The construction of the main ramp has significantly enhanced the mechanization and efficiency of mining operations. At a modern, large-scale mine, the main ramp stretches over 5,000 meters in length, stands 8 meters wide, and features a 10% gradient. It is equipped with state-of-the-art ventilation, lighting, and drainage systems. Thanks to this advanced infrastructure, large trucks can now directly transport ore from underground mining faces to the surface, while equipment like loaders can swiftly reach various work areas. As a result, the mine’s operational efficiency has soared, labor intensity has been markedly reduced, and both ore losses during transportation and equipment wear have been minimized.

4. Blind Shaft / Blind Inclined Shaft

A blind shaft and a blind inclined shaft refer to deep shafts that have no surface exit, primarily used for developing ore bodies located beneath already-mined areas in the upper sections. During mining operations, once the upper ore bodies have been fully extracted, constructing a blind shaft or a blind inclined shaft becomes essential to further exploit the deeper mineral resources. A blind shaft is a vertical deep shaft, while a blind inclined shaft is an angled deep shaft—both are connected to the main shaft via stage-level transport drifts, creating a comprehensive transportation and hoisting system. Utilizing the hoisting equipment and associated facilities of the main shaft, this system efficiently facilitates the extraction of deep-seated ores as well as the movement of personnel and equipment. The construction of blind shafts or blind inclined shafts requires careful consideration of seamless integration with existing shafts and drifts, as well as the geological conditions and mining technology requirements specific to the targeted deep-seated ore bodies. For instance, in a certain mine’s deep-extraction project, a 300-meter-deep blind shaft was constructed and linked to the upper main shaft via stage-level transport drifts, successfully enabling efficient extraction of the deep-lying ore bodies and ensuring sustainable growth for the mine.

(II) Tunnel-Type — The Backbone of the Horizontal Transportation Network

The roadways underground primarily handle horizontal transportation tasks, with the main transport roadways and the shaft bottom car shed serving as the critical backbone that forms the underground horizontal transportation network. Working in tandem, they ensure the efficient movement and circulation of ore, personnel, and materials throughout the mine.

1. Main Transport Roadway

The main transport roadways are horizontal tunnels laid out along the ore body’s strike or at specific mining stages, including stage transport drifts and main transport crosscuts. Stage transport drifts typically run parallel to the primary ore body and serve as one of the key underground routes for transporting mined ore. They directly handle the task of conveying ore extracted from the working faces down to the bottom-of-shaft car shed or other transfer points. The cross-sectional dimensions of these drifts must be carefully designed based on factors such as the type and specifications of transportation equipment, as well as ventilation requirements, to ensure smooth and safe operations. Meanwhile, the main transport crosscuts are horizontal tunnels that penetrate through rock layers, connecting the ore body to the shaft. These crosscuts play a crucial bridging role in the underground transportation network, enabling ore from different areas to converge via the crosscuts onto the main transport routes, thus facilitating centralized and efficient ore transportation.

For example, in a large-scale coal mine, the stage transportation drifts were designed with an arched cross-section, measuring 5 meters in width and 4 meters in height, ensuring smooth passage for both large mining trucks and belt conveyors. The main transport stone gate, stretching 500 meters in length, connects multiple mining sections to the main shaft, creating an efficient transportation network capable of moving over 10,000 tons of coal daily—and thereby supporting the mine’s high-yield, high-efficiency production operations.

2. Wellhead Yard

The shaft bottom yard, serving as the vital link between the shaft and the main transportation roadways, is the central node of the underground transportation system. It typically includes car storage tracks, shunting tracks, and a series of associated chambers, such as unloading chambers and ore bins. The car storage tracks are used to park mine cars waiting for transport or unloading, while the shunting tracks handle the scheduling and redirection of these cars, ensuring they enter and exit the shaft bottom yard in an orderly manner. The unloading chamber facilitates the transfer of ore from mine cars into hoisting containers or other transport equipment, enabling seamless ore handling. Meanwhile, the ore bins play a crucial role in regulating the pace of ore transportation and temporarily storing ore, thereby preventing production disruptions caused by equipment failures or other unforeseen issues. A well-designed and efficiently operated shaft bottom yard is essential for enhancing underground transportation efficiency and maintaining the continuous operation of mine production.

At the bottom car shed of a certain metal mine, multiple storage tracks and shunting lines have been designed, capable of accommodating over a hundred mine cars simultaneously. The unloading chambers are equipped with automated unloading equipment, enabling the removal of thousands of tons of ore per hour. Meanwhile, the ore bins boast a capacity of tens of thousands of tons, effectively balancing the unevenness in ore transportation. This ensures stable mine operations, allowing for smooth hoisting and transport of ore—even during peak periods of demand.

(III) Chamber-type Structures —— Vessels of Core Functional Facilities

A chamber is a specially designed space excavated underground, serving specific functions. Among these, production service chambers and storage, loading, and transportation chambers are indispensable components of the primary development roadways, housing a variety of essential facilities that provide critical support for the mine's normal operations.

1. Production Service Chamber

The production service chambers primarily include the in-pit crushing chamber, hoisting chamber, and unloading chamber, among others. The in-pit crushing chamber is used for the primary crushing of mined ore, breaking large chunks into a particle size suitable for transportation and subsequent processing—thereby enhancing both transport efficiency and the convenience of downstream operations. For instance, at a large copper mine, the in-pit crushing chamber is equipped with massive jaw crushers and cone crushers, capable of handling thousands of tons of ore per hour. After the large ore pieces are crushed to the appropriate size, they are conveyed via belt conveyors directly to the shaft bottom yard. The hoisting chamber serves as the installation site for lifting equipment such as hoists and winches, which are responsible for transporting ore, personnel, and machinery from underground levels to the surface—or for transferring them between different working horizons. To ensure stable operation of the equipment and safeguard workers, the hoisting chamber must be outfitted with robust ventilation, lighting, and safety protection systems. Lastly, the unloading chamber plays a crucial role in transferring ore from transport vehicles into hoisting containers. Through the thoughtful design of its structure and equipment layout, this chamber enables rapid and efficient ore unloading, significantly reducing both transportation time and associated costs.

2. Storage and Shipping Chamber

The storage and transportation chambers primarily include the ore bin & transfer chamber, as well as the main ventilation fan chamber. The ore bin and transfer chamber play a crucial role in regulating the pace of underground transportation and serving as a transit point for ore movement. The ore bin is designed to store a specific quantity of ore, helping to smooth out fluctuations and imbalances in the production process, thereby ensuring continuous operations for subsequent processing and transportation. Meanwhile, the transfer chamber is responsible for transferring ore from one type of transport equipment to another, facilitating seamless transitions between different transportation methods. For instance, in a certain coal mine, the ore bin has a capacity of 50,000 tons, effectively meeting the mine's production needs for several days and significantly alleviating transportation pressures. The transfer chamber is equipped with high-efficiency transfer devices, such as transfer machines and chutes, enabling rapid reloading of coal from belt conveyors onto mine cars, thus achieving smooth and uninterrupted transportation flows. As for the main ventilation fan chamber, it houses the primary ventilation fans, which are essential for supplying fresh air underground while exhausting stale air, thereby maintaining optimal air quality and safeguarding the health of workers in the mining environment. The location of the main ventilation fan chamber must be carefully optimized based on the mine’s ventilation system and roadway layout, ensuring maximum ventilation efficiency. Additionally, the chamber should be fitted with comprehensive ventilation ducts and control systems, allowing precise regulation of airflow volume and direction to meet operational requirements.

II. Collaborative Support: Assisting in the Classification and Function of Roadway Excavation

Auxiliary development roadways serve as a powerful complement to the main development roadways. Although they do not directly handle the primary tasks of ore transportation and hoisting, they nonetheless play an indispensable role in the entire mine production system. Think of them like the capillaries in the human body—though their diameter is smaller than that of the aorta, they are intricately distributed throughout various tissues, providing essential support for the body’s seamless functioning. Auxiliary development roadways primarily include three major types: shafts, tunnels, and chambers. Each type boasts unique functions and purposes, yet they work together harmoniously to ensure the safe and efficient operation of mine production.

(1) Shaft-Type —— Dedicated Channel for Auxiliary Functions

In shaft-type auxiliary development roadways, the secondary shaft, ventilation shaft, and dedicated drainage shaft each fulfill unique roles, serving as critical passages that ensure safe production and operations in the mine.

1. Auxiliary Shaft

The secondary shaft plays a vital role in mine production, with cage hoisting serving as its primary transportation method. Its tasks are both extensive and critical. In terms of personnel movement, it serves as the main access route for miners entering and exiting the mine shaft—every day, hundreds or even thousands of workers safely ascend and descend between the surface and underground work areas via the secondary shaft's cages. When it comes to transporting materials and equipment, everything from massive mining machinery to small tools and components, as well as steel supports for tunnels and various chemicals used in production, relies on the secondary shaft for delivery. Additionally, the shaft is responsible for removing waste rock generated during underground mining operations, ensuring that the working space remains clean and safe. Many mines also repurpose their secondary shafts as intake airways, continuously supplying fresh air to the depths of the mine and maintaining high-quality air conditions for underground operations. To guarantee safety, secondary shafts are typically equipped with ladder compartments, allowing workers to evacuate swiftly in emergencies. Moreover, they often include pipe shafts to accommodate ventilation, drainage, and water supply systems. During a recent unexpected power outage at one mine, the ladder compartment in the secondary shaft proved crucial: miners were able to evacuate in an orderly manner through the ladders, preventing any injuries or fatalities.

2. Ventilation Shaft

Ventilation shafts are critical facilities that ensure underground air quality and operational safety, and they are categorized into return air shafts and dedicated intake shafts.

Return air shaft: Specifically designed to exhaust contaminated air from underground mines, the mining process generates significant amounts of harmful gases such as carbon monoxide and hydrogen sulfide, along with airborne dust. The return air shaft is equipped with powerful ventilation fans that extract this polluted air and release it into the atmosphere. To ensure rapid reversal of airflow in emergency situations, the return air shaft is also fitted with a reverse-flow device. When selecting the site for the return air shaft, its entrance must be carefully positioned—avoiding the main shaft's industrial area—to prevent the discharged contaminated air from polluting the surrounding environment. In one particular metal mine, the return air shaft is outfitted with two high-capacity fans capable of expelling all the underground pollutants within minutes, thereby maintaining a safe working environment below ground.

Dedicated intake shaft: Its responsibility is to deliver fresh airflow to the deep underground working areas, working in coordination with the return air shafts to create either a diagonal or central ventilation system. In some large-scale mines, where underground work areas span vast distances and reach considerable depths, dedicated intake shafts—through carefully planned layouts and strategically placed ventilation ducts—transport fresh air from the surface directly to each operational zone. This ensures that miners can breathe clean, healthy air, boosting both productivity and overall well-being. For instance, one coal mine has implemented a diagonal ventilation system, with dedicated intake and return shafts positioned at opposite ends of the mining field. This setup has significantly improved underground ventilation conditions, effectively reducing methane concentrations and minimizing safety risks.

3. Dedicated Drainage Well

Dedicated drainage wells are a critical safeguard for ensuring safe mine operations, typically featuring vertical or inclined shaft structures. Inside these wells, drainage pipes are installed—acting like the mine’s "blood vessels"—collecting water that flows from various underground stages and efficiently conveying it out of the mine. During mining activities, groundwater, surface water, and wastewater generated during production continuously seep into the mine. To address this, dedicated drainage wells must work closely with the pump room at the bottom of the shaft and the water reservoir. Once water accumulates in the reservoir, multi-stage drainage pumps in the pump room lift the water up to the dedicated drainage well, from where it is ultimately discharged back to the surface. During the rainy season, when a mine experiences a significant surge in water inflow, the dedicated drainage wells and pump room operate in seamless coordination, providing round-the-clock, uninterrupted drainage. This proactive approach has effectively prevented the risk of flooding, ensuring the mine can maintain normal production without interruption.

(II) Alleyway Category – Specialized Service Branch Network

Auxiliary development roadways mainly include non-main transportation roadways and functional roadways—they act like the "capillaries" of the mine, extending deep into every stage of production and providing specialized services to ensure the mine's smooth operation.

1. Non-main transportation roadways

Non-main transportation roadways primarily include stage auxiliary drifts and ground pressure monitoring tunnels, both of which play an indispensable role in mine production. The stage auxiliary drifts serve as a "bridge" connecting the main transport roadway to the mining areas, mainly handling auxiliary transportation tasks—such as moving materials and equipment from the mining area to the main transport roadway, or transferring supplies from the main roadway back into the mining zone. Meanwhile, the ground pressure monitoring tunnels act as the mine's "monitoring stations," equipped with various sensors like pressure gauges and displacement meters to continuously track the stress and deformation of surrounding rock masses, providing critical scientific data for effective ground pressure management. Typically, these roadways feature smaller cross-sectional dimensions compared to the main transport roadways, as their design focuses more on meeting the specific needs of particular production stages—for instance, the stage auxiliary drifts are tailored to accommodate the passage of compact transport vehicles, while the ground pressure monitoring tunnels prioritize ease of installation and maintenance for the monitoring equipment.

2. Functional Alleys

Functional roadways include filling roadways and drainage-dewatering roadways, both of which play a critical role in mining operations and water control efforts at mines.

Filling Roadway: It serves as the critical passage in the filling mining method, connecting the surface filling station at one end and leading to the underground mined-out areas at the other. During the filling mining process, the filling drift is responsible for transporting the prepared cemented or non-cemented backfill materials—such as tailings, crushed stone, and others—from the surface to the mined-out zones via pipelines or mine cars, where they are used to fill the voids. This not only supports the surrounding rock, preventing surface subsidence, but also helps enhance the recovery rate of mineral resources. In a particular mine employing the filling mining method, the filling drift can deliver thousands of cubic meters of backfill material into the mined-out areas daily, effectively managing ground pressure and ensuring the sustainable operation of the mine.

Drainage and Dewatering Roadway: Primarily used to mitigate the risk of water-related hazards during mine extraction, these systems are typically laid out along aquifers. By constructing boreholes within the drifts, groundwater from the aquifer is directed into the drifts, and then efficiently pumped out to the surface via drainage equipment, thereby dewatering the underground water. In mines with complex hydrogeological conditions, building drainage and dewatering drifts can effectively lower the groundwater table, reducing the impact of water inflows on mining operations and significantly enhancing mine safety. For instance, a certain metal mine first constructed drainage and dewatering drifts prior to mining. After an extended period of dewatering, the groundwater level was lowered by several meters, creating ideal conditions for subsequent mining activities.

(III) Chamber-type —— Auxiliary Production and Support Facilities

Auxiliary development roadways of the chamber type are critical facilities that ensure the smooth operation of auxiliary mining operations. They include safety and emergency chambers, production-support chambers, and service-oriented chambers—essentially serving as the mine’s “logistics support center,” providing comprehensive assistance for safe and efficient production.

1. Safety Emergency Chamber

The safety emergency chamber, comprising a pump room and a disaster-avoidance chamber, serves as the last line of defense for safe mining operations. As the core facility for flood prevention and drainage in mines, the pump room is equipped with multi-stage drainage pumps that efficiently remove underground water surges to the surface. To ensure reliable operation during emergencies, the pump room is typically outfitted with backup power supplies and multiple drainage pumps capable of handling water inflows of varying scales. Meanwhile, an accompanying water reservoir is designed to store mine water based on the specific volume of inflow and the mine’s drainage capacity. The disaster-avoidance chamber, on the other hand, provides an emergency shelter for personnel in the event of a catastrophic incident. Inside, it is fully stocked with essential supplies such as oxygen generators, communication devices, food, and drinking water—enough to sustain workers for an extended period. The construction of the disaster-avoidance chamber must adhere to stringent fireproofing, waterproofing, and airtightness standards, guaranteeing that it can offer a secure refuge even under extreme disaster conditions. For instance, when a mine experienced a sudden water-inrush accident, the trapped workers promptly took shelter in the disaster-avoidance chamber. Relying on the chamber’s abundant supplies and robust communication systems, they maintained contact with the outside world until their successful rescue.

2. Production Auxiliary Chamber

Production support chambers include repair chambers, substations, and explosive storage facilities, each playing a critical supporting role in the mine's operational processes. The repair chamber is primarily used for the maintenance and repair of trackless equipment—such as trucks and loaders—that require regular upkeep during prolonged operation. Equipped with specialized repair equipment and tools, the chamber ensures comprehensive inspections and maintenance, keeping these machines running smoothly and efficiently. The substation serves as the core hub for underground power distribution, responsible for converting high-voltage electricity delivered from the surface into lower voltages suitable for use by underground equipment—and then distributing this power accordingly. To guarantee safety, substations must feature robust ventilation systems, along with fireproof and moisture-resistant designs. Meanwhile, the explosive storage facility is dedicated to storing and issuing blasting materials. It is divided into two distinct areas: a storage zone, where explosives and detonators are kept under strict adherence to mandated safety distances and storage conditions; and a distribution zone, which handles the secure delivery of blasting materials directly to the blast sites. To prevent potential hazards, the explosive storage facility requires independent ventilation systems, while its overall layout must comply with stringent mine safety regulations, maintaining adequate safety distances from other structures and facilities.

3. Service-type Chamber

Service-oriented chambers include the underground duty room and the tool library, both of which provide convenient support for the mine’s daily operations. The underground duty room serves as the central command hub for on-site production, responsible for real-time monitoring of underground conditions and coordinating tasks across all production stages. Here, operators keep a close eye on equipment status, personnel locations, and other critical information, promptly addressing any emergencies to ensure smooth operations. Meanwhile, the tool library is specifically designed to store a wide range of small tools and materials—such as wrenches, screwdrivers, cables, and more—enabling workers to quickly access what they need when required. Typically located close to the working areas, the tool library enhances operational efficiency by minimizing delays caused by searching for tools. For instance, during a recent equipment malfunction repair at one mine, staff swiftly retrieved the necessary tools from the library, allowing them to promptly fix the issue and maintain uninterrupted production.

III. Classification Logic and Engineering Application Principles

(1) Function-Oriented Classification

In underground mining projects, functional orientation serves as the key criterion for distinguishing between primary and auxiliary development roadways. Primary development roadways are centered around the core function of ore transportation and hoisting—they act as the lifeblood of mine production, and their construction and operation directly determine the mine's production capacity and economic efficiency. In contrast, auxiliary development roadways revolve around supporting functions such as ventilation, drainage, and the transport of personnel and materials. Though relatively smaller in diameter, these auxiliary roadways resemble the capillaries in the human body: they are extensively distributed throughout various "tissues," providing comprehensive support to ensure the smooth and efficient operation of the primary roadways. The two types of roadways are interconnected via critical nodes like the shaft bottom car shed and stage-level transport tunnels, forming an organically integrated system.

(II) Ore Body Suitability

Different types of development drifts have varying requirements depending on the orebody’s occurrence conditions. Adit development is suitable for high-mountain regions with significant topographic differences, where the orebody lies above the adit level. By leveraging the natural slope of the adit, ore can be transported by gravity, offering advantages such as low costs and high efficiency. The choice between shaft and inclined shaft development, however, primarily depends on the dip angle of the orebody: when the dip is steep, a vertical shaft is more appropriate, as its straightforward shaft structure enables efficient ore hoisting; conversely, when the dip is gentle, an inclined shaft becomes more economical, since its inclined design facilitates smoother operation and transportation of equipment. Meanwhile, ramp construction is mainly designed to meet the needs of trackless mining operations, making it ideal for cases where the orebody is shallowly buried and extends over a long strike length—thus enhancing the mechanization and efficiency of mining activities. Lastly, blind shafts are specifically established to address the challenge of developing deep-seated orebodies. Once the upper orebodies have been fully mined, these blind shafts connect to the main shaft system, enabling the efficient extraction of resources from deeper levels. In practical engineering applications, it is essential to comprehensively evaluate factors such as the orebody’s geological conditions, mining technology requirements, and economic considerations, in order to select the most suitable type of development drift that ensures highly efficient mining operations.

(III) Balancing Safety and Efficiency

Auxiliary roadways and chambers play a critical role in ensuring safe mining operations, and their design and construction must strictly adhere to the requirements of relevant standards such as the "Safety Regulations for Metal and Non-Metallic Mines." The wind speed design for ventilation shafts must be precisely calculated based on the air demand at underground working faces and the associated ventilation resistance, ensuring that underground air quality meets regulatory standards and providing miners with a safe working environment. Meanwhile, the head design for drainage shafts should thoroughly account for both the volume of groundwater inflow and the required pumping height, equipping the system with drainage equipment capable of handling unexpected water-related emergencies. Under the prerequisite of meeting safety requirements, optimizing the layout of auxiliary roadways and chambers—such as rationally planning the ventilation system to minimize resistance or fine-tuning the drainage system to enhance efficiency—can effectively reduce unnecessary construction work, lower overall project costs, and boost the mine's operational efficiency. The classification system for development roadway and tunnel engineering serves as the foundation for mine design and construction, directly influencing key factors like mining costs, safety levels, and production efficiency. By clearly defining the functional boundaries between primary and auxiliary roadways and establishing effective coordination mechanisms, we can achieve highly efficient utilization of underground space resources, providing systematic support for modern mine construction and ultimately driving the sustainable development of the mining industry.