Can mobile scaffolding be used on uneven ground? How to adjust?
Mobile scaffolding can be used on uneven ground, but it needs to be scientifically adjusted to ensure the stability of the scaffolding and avoid safety accidents such as tilting and collapse caused by uneven stress. Specific adjustments should be made based on ground drop, work height, and load conditions. The following are detailed methods:
1、 Ground assessment and preparation before use
Before using mobile scaffolding on uneven ground, it is necessary to evaluate the ground conditions:
Allowable drop range: The height difference between each support point at the bottom of a single set of scaffolding should not exceed 5cm (special treatment is required if it exceeds this range), and the ground bearing capacity should be ≥ 0.5MPa (about 50kN/㎡, and soft soil should be compacted or reinforced in advance).
Cleaning and troubleshooting: Remove ground obstacles (such as stones, accumulated water in depressions) to avoid wheel jamming; If the ground has a slope (slope ≤ 5 °), priority should be given to placing the frame in the direction of the slope to reduce the risk of lateral tilt.
2、 Core adjustment method: graded handling of uneven issues
1. Slight unevenness (drop ≤ 3cm): Use self adjustment function
Base screw adjustment: The bottom of the vertical pole of the mobile scaffold is usually equipped with an adjustable screw (length ≥ 15cm). Clockwise rotation of the screw can raise it, and counterclockwise rotation can lower it. By adjusting the height of the screw rods of different uprights, the top horizontal bar of the frame is kept horizontal (measured with a level ruler, with an error of ≤ 2mm/m), ensuring that each fulcrum is evenly stressed.
Wheel height adjustment: If there is a small gap between the wheel seat and the ground, a thin iron sheet (thickness 1-3mm) can be placed under the wheel axle to increase the fit between the wheel and the ground and avoid a single wheel hanging in the air.
2. Moderate unevenness (3cm ＜ drop ≤ 5cm): auxiliary cushion height and force balance
Partial elevation method: Lay hard cushion blocks (such as steel plates or precast concrete blocks, with a thickness not exceeding 5cm and an area ≥ 0.3 ㎡) at lower support points. The cushion blocks should be flat and closely attached to the ground, and the use of easily breakable materials such as bricks and stones is prohibited. After raising, use a screw to fine tune again to ensure that the verticality of the frame meets the requirements (deviation ≤ 1/100 height).
Span adjustment: If the ground tilt causes a large drop between adjacent poles, the span of the frame can be appropriately reduced (such as adjusting from 1.8m to 1.5m) to reduce the stress span of a single pole and enhance overall stability.
3. Severe unevenness (drop>5cm): Special reinforcement and restricted use
Segmented leveling and connection: Split the frame into multiple short sections, level each section separately according to the ground height, and firmly connect the sections with rigid connectors (such as pole docking clips) to form a stepped structure. At the same time, each section of the frame needs to be separately equipped with wheel brakes and anti slip wedges to prevent relative sliding.
Restricted operating conditions: At this time, it is prohibited to use it for operations with a height exceeding 3 meters, and the operating load must be reduced by 30% (such as adjusting the original rated load of 5kN to 3.5kN) to avoid deformation caused by excessive local stress.
3、 Stability verification after adjustment
Static testing: After the adjustment is completed, push the top of the frame by hand (apply a force of about 500N in the horizontal direction), and there should be no obvious shaking of the frame, and there should be no suspension or settlement of each fulcrum; Use a level to check the work platform and ensure there is no tilt (tilt ≤ 1 °).
Dynamic testing: 1-2 operators stand at the edge of the platform (simulating partial load), observing whether there is any abnormal noise or deformation at the connection between the vertical and horizontal poles, and whether the wheel brakes have failed.
Environmental adaptation: If it is outdoors, it is necessary to additionally check the impact of wind loads (stop using when the wind force is ≥ 5 levels), and add windproof cables at the bottom of the frame, which are connected and fixed to the ground anchor points.
4、 Taboos and Precautions
It is prohibited to forcibly adapt uneven ground by dismantling wheel sets, cutting upright poles, etc., as this will damage the structural strength of the frame;
The cushion block should be tightly attached to the ground and the bottom of the frame, and it is forbidden to stack more than 3 layers of cushion blocks (which are prone to instability);
After adjustment, it is necessary to mark "use on uneven ground" in a prominent position on the frame to remind operators to pay attention to load restrictions;
After each movement, the height of each pivot must be rechecked and adjusted, and the previous adjustment parameters cannot be used.
Through the above methods, mobile scaffolding can be safely used on uneven ground, with the core principles of "graded adjustment, uniform force distribution, and strengthened fixation". It needs to be flexibly operated according to actual working conditions, and always follow the "Technical Code for Safety of Construction Tool Scaffolds" (JGJ202) as the standard to ensure the stability of the scaffolding and the safety of operations.
