Distribution of land stability based on standard penetration value (SPT) with various depth in Semarang city, Indonesia

Abstract Land stability is one of the main determining factors for the bearing capacity of the environment. The land stability is influenced by the condition and characteristics of the resources in the environment. The supply capacity in terms of the level of land stability for spatial use allocation has been based on the capacity of land for agriculture and the physical aspects of the land. It accordance with the local regulation i.e. no. 17 of 2009. Land stability includes the ability of land for agriculture and the physical aspects of land, as well as the stratigraphy of subsurface soil mass, especially geological characteristic. The research was conducted in Semarang City Indonesia by drilling and standard penetration test (SPT) and taking 448 undisturbed samples (UDS’s) of soil that scattered in the research area. Analysis of UDS’s have been carried out in the laboratory to obtain comparisons with SPT values in determining the level of land stability both vertically and horizontally. Soil types obtained are clay, silt, silt-sand, sand, and sand stone with a level of consistency and density in accordance with the measured SPT. Land stability values ranged from 0.201 kg/cm2-14.248 kg/cm2 covering all types of soil with different consistencies and density. The distribution of land stability is given in an infographic to get an overview of the land stability levels geographically at a depth of 2.5m, 5.0m, 7.5m, and 10.0m. This infographic can be useful for spatial evaluation, engineering guidance, and environmental research in Semarang City, Indonesia.