Ground Instability Causes and Reinforcement, Correction Methods
The support structure for outdoor billboards is commonly referred to as the foundation. These are grounded on soil or rock, further categorized into artificial and natural foundations; whereas, building billboards and wall billboards rely on the rooftop and wall structures for their foundations. For outdoor billboards, the foundation's placement is crucial, as it directly impacts their proper functioning.
Common foundation engineering accidents on billboards are often caused by the following reasons: insufficient bearing capacity of the foundation leading to instability; excessively soft soil in the foundation, which, after long-term negative pressure, causes the foundation to tilt; changes in the surrounding geological environment leading to expansion or contraction deformation of the foundation soil; loose or damaged supports of wall-mounted billboards; uneven settlement of building billboards due to external forces (including strong winds, rough construction, etc.).
The occurrence of basic engineering accidents is primarily due to improper surveying, design, construction, or changes in the usage environment. After instability in the foundation is detected, it is essential to reinforce and correct the outdoor billboard's foundation promptly. Before determining the implementation plan, the following investigations should be conducted:
(1) Investigate the soil and hydrological conditions of the area where the foundation is located.
(2) Review original documents to understand the foundation type and load-bearing conditions of the billboard, as well as its design load capacity.
Inspect the quality of construction materials used during billboard construction, weather conditions during the construction period, and the overall construction quality of the billboard.
(4) Investigate changes in the surrounding environment during the billboard's usage, such as the construction of municipal facilities, the commencement of nearby building projects, fluctuations in groundwater levels, and changes to the ground drainage systems.
