Borrow Pit Agreement
A one-storey fence and building threatened with slippage are located in Ogbulubi Square, about 20 metres from the edge of the abandoned loan mine (Figure 7A). Due to the fact that heavy goods vehicles such as bulldozers, payloaders and trucks have been used for excavation and loading of lateritary soil on designated construction sites, the devices tend to cause vibrations that send side waves to surrounding structures, which also weaken the foundations of structures and cause displacement. During the rainy season, the micro-cracks produced become water infiltration pathways and eventually create cracks that cause the mine`s inclination to fail. Slope failure incidents that cause landslides can lead to the collapse of structures such as buildings, roads, and the drainage system, which certainly results in a huge economic loss for homeowners. On one of the abandoned rental pits on the Owerri-Okigwe motorway is a high-voltage mast (Figure 7B). From the edge of the pit to the high-voltage mast there is a distance of about 15 m. There is a thick cover of Indian bamboo vegetation that tends to stabilize the soil, but this cannot prevent slippage as soon as it is spilled. The high-voltage mast poses a major threat to local residents and commuters using this road. The economic and social risks associated with the situation of these high-voltage electricity pylons are enormous and should not be compromised. Some of these loan mines have been living for decades, with demolition and subsequent reactivation, so that the land material can be used elsewhere.
With the increase in population and the improvement of road infrastructure in many developing countries, active and abandoned credit mines are numerous everywhere. Several hectares of land are degraded by abandoned loan mines that become ponds or landfills. In this study area, Ihiagwa and Emekuku dug like the largest, but the pits are neither planned nor professionally designed. Loan mine operators have operated an unsustainable engineering practice and left the environment hazardous for years to human habitation and ecosystem services. This has led to several potential risks to the environment and geo-environment, visible in the event of motorway breakdowns, landslides, erosion, surface and groundwater contamination, human accidents and other stray animals, threatening biodiversity. There is therefore a great need to study the environmental risk factors of closed mines and to promote the idea of site recovery and remediation soon after the completion of mining. In general, fillers must be free of organic matter, meet the California Minimum Bearing Ratio (CBR) and have an acceptable plasticity index. The lower filling consists of a mixture of sand or sand with gravel that inhibits the growth of plants or other plant matter.13 Excavation and careful design of pit slopes can reduce landslide accidents. Deep loan pits often with a negative slope support frequent landslides. Landslide is a geological phenomenon that occurs as a result of groundwater movements and is common in large abandoned and active loan pits.