Large granite bases feature heavy dead weight and brittle material properties. Their finished datum surfaces are ultra-precision ground. Many easily overlooked risks exist during transportation and on-site installation. Improper handling may lead to scratches on the reference surface, or invisible internal microcracks inside the stone. After commissioning, the precision will drift continuously, and even fracture may occur. With years of project delivery experience, ZHHIMG has established a complete set of protection and control schemes to avoid hidden hazards from factory shipment to on-site positioning.
During packaging and transportation, the primary risk comes from improper support and fixation. Many ordinary freight packages simply use soft padding without custom brackets designed according to the force characteristics of the base. Vehicle vibration during transit concentrates stress on partial areas of the base and induces hidden internal cracks in the stone. Meanwhile, if the ground datum surface directly touches hard packaging materials, friction during transport will destroy its nanometer-level flatness. Long-distance transportation also involves temperature changes. Due to the large volume of granite, different parts of the stone heat up and cool down at different rates, causing temporary thermal deformation. Poor packaging sealing leads to deformation caused by day-night temperature fluctuation and distorts initial inspection results after arrival. ZHHIMG designs rigid transport brackets customized to the shape and weight of each base. Support points follow the force layout adopted during machining to avoid overloaded local stress. Precision reference surfaces are fully wrapped with flexible protective materials, and shock-absorbing structures are added to outer packages. Transport routes with stable temperature and low road vibration are preferred to reduce damage induced by bumping and temperature difference.
After arrival at the site, lifting operations represent another high-risk stage. Random selection of lifting points for large granite bases will create bending stress and easily crack the brittle stone. Direct binding of steel wires around base edges will squeeze and chip stone corners, damaging edges and the junction with reference surfaces. On-site lifting environments are complex; factory space, floor bearing capacity and surrounding equipment all bring interference. Insufficient floor bearing capacity or temporary shims with low rigidity lead to sudden force changes when the base is lowered into place, triggering internal damage. ZHHIMG supplies dedicated lifting tools and force-bearing schemes. Steel wires are not allowed to directly contact the stone body. Before operation, technicians evaluate factory floor load capacity and space conditions. Lifting, translation and landing are carried out slowly and steadily. Impact, shaking and twisting of the base are avoided throughout the process. Forcible pushing to adjust position after landing is forbidden to prevent friction damage to the base bottom. 
Risks during positioning and leveling mostly arise from neglected support structures and environmental conditions. Scattered shims are often used to support the base on site. Insufficient shim quantity, uneven thickness or impurities on contact surfaces create unbalanced force distribution under the base’s self-weight and induce continuous bending deformation. Even if the flatness reading is qualified at the time of leveling, the plane will gradually shift once the force state changes. Temperature fluctuation and direct airflow from air vents on site create gradient temperature differences on granite. If leveling and calibration are not completed after temperature stabilization, measurement data will be distorted and lead to wrong judgment of base precision. Continuous floor vibration from nearby machine tools or air compressors distorts readings during leveling and may slowly shift the support positions of the base. ZHHIMG technicians adopt multi-point uniform support layout for on-site positioning and clean contact surfaces of supports. Leveling and geometric tolerance recheck start only after the base temperature fully balances with ambient conditions. Vibration sources and direct airflow are avoided to maintain stable leveling status.
Hidden hazards also exist during base fastening and subsequent equipment assembly. When locking heavy components such as columns and modules onto the base, improper bolt tightening sequence and torque control will generate concentrated compressive stress locally on granite. Excessive torque may crack bolt holes. Some projects rush construction and start machine assembly immediately after the base is put in place without sufficient settling time. Temporary stress generated during lifting and transportation cannot be released. After assembly and loading, the reference geometry changes slowly and the machine’s repeat positioning accuracy degrades continuously. ZHHIMG provides on-site assembly guidance and specifies procedures for stepwise diagonal bolt tightening with torque limits. A settling period is reserved after base positioning. Subsequent installation of gantries and modules can only start after stress is fully released and re-inspection of geometric indicators passes, protecting the long-term precision stability of granite bases.
Post time: Sep-20-2026