Choosing the right excavator is not only a crucial part of earthwork operations for roadbed construction but also key to providing the optimal construction solution. The selection of the excavator model and the use of supporting equipment should be determined based on the construction environment and the available vehicles on site.
Based on the Construction Environment
The construction environment determines the operational efficiency of the excavator. Different models and configurations should be selected according to varying site conditions to avoid unnecessary waste.
1. Loose, low-density soil or sand and gravel, large work volume, limited schedule. Large high-power excavators with bigger bucket capacities are recommended to maximize operational efficiency. Examples include 20-ton excavators with 1.2 m³ buckets, 30-ton with 1.6 m³, and 40-ton with 2.2 m³.
2. Loose, low-density soil or sand and gravel, intermittent operations, rental projects. Medium and small-sized excavators can be used to save construction costs. Examples include 20-ton excavators with 0.85 m³, 0.93 m³, or 1.1 m³ buckets.
3. Hard soil, weathered rock, sand with stones, frozen soil, blasted or crushed rock. Excavators with high digging force and reinforced attachments should be selected. Bucket capacities can be slightly smaller (rock buckets) to handle harsh conditions efficiently. Examples include 20-ton with 0.9 m³, 30-ton with 1.2 m³, and 40-ton with 1.6 m³.
4. Special environmental conditions. For extreme conditions such as high altitude (above 3000 meters), high temperature (over 45°C), high humidity, acidic or alkaline soils, or extreme cold (below -10°C), specific measures should be adopted to reduce environmental impact on equipment. Examples include pressurized radiators, large fans and pulleys, reduced fuel supply, and preheating of air intake and engine oil.
Based on Supporting Vehicles on Site
Excavators are usually used in conjunction with transport vehicles. Selecting the appropriate excavator model based on work volume, transport distance, and vehicle capacity is crucial.
1. Large work volume, short transport distance, sufficient transport vehicles. Multiple large excavators should be used to maximize efficiency. Examples: 20-ton with 1.2 m³, 30-ton with 1.6 m³, and 40-ton with 2.2 m³.
2. Large work volume, long transport distance, insufficient transport vehicles. Multiple medium-sized excavators can match transport capacity to save costs. Examples: 20-ton with 1.1–1.2 m³ buckets, or a combination of a few 30-ton excavators and several 20-ton excavators working together.
3. Spoil operations. Medium excavators with fast operating speeds and high efficiency are recommended. Examples: 20-ton with 0.85–1.2 m³ buckets.
Since construction environments vary, adjustments should be made based on local conditions to ensure the best possible construction solution.
