Assessment of Infrastructures Assets Induced by Water Level Fluctuation along the Bengawan Solo River

Abstract

The stability of infrastructure along river channel, such as bridges and embankments, is paramount to continuing service and public safety, and therefore, is essential consideration in the design, construction and maintenance. During the design process, infrastructure stability is often assumed to be static, and considered by implementing a safety factor which is produced by an analysis of extreme condition. However, this has failed to consider the variability of natural factors and importantly, the escalating threat of extreme environmental condition, induced by global climate change. This assumption should, therefore, be revisited for developing a more resilient design and maintenance regime. To demonstrate the changing infrastructure stability, an assessment of safety factor of river embankment and bridge foundation as nearby infrastructures along Bengawan Solo River's channel and estuary is presented. This was undertaken to determine the impact of water level fluctuation during two extreme conditions during dry and rainy seasons in several critical locations. The river characteristics (i.e. morphology, water fluctuations, velocity, and sub-soil characteristics), embankment conditions and bridge pile foundation were investigated in-situ to assess the change of safety factor. The laboratory investigation focused on river and embankment characteristics including the analysis of the drying-wetting conditions. In-situ and laboratory investigations found an extreme condition which the infrastructures are subjected into, where the water level and flow velocity were 3 m and 0.04 -0.27 m/s during dry season; and 10 m and 0.46 -0.84 m/s during rainy season. Furthermore, from the analysis, it can be concluded that certain areas in the river do not meet the minimum requirements for bridge foundation and embankment stability.

Analysis of Existing Slope Reinforcement Design on Clay Shale Soil and Its Alternative Modifications: A Case Study of the Awunio – Lapuko Road Section Sta 4+955 – 5+015 in the Southeast Sulawesi Province

“…where: Qult = ultimate bearing capacity Qs = friction piles Qp = end bearing piles Wp = weight of the pile Then, to obtain the allowable single pile capacity, it is determined using the following formula: Qa = Qult/SF … (11) where: Qa = bearing capacity of single pile SF = 2,5 -3 safety factor The frictional resistance or the skin friction resistance of a pile can be calculated using the formula:…”

“…The landslide is suspected to occur due to the contact between clay shale soil and water entering the road body through cracks on the surface, transforming the soil condition beneath the road body as if it were sandy. The Mechanism of water infiltration could decrease the strength of soil rapidly (Satrya et al, 2019). Clay shale soil is highly sensitive to weather changes or exposure to air and water.…”

Existing Design Analysis of Slope Reinforcement on Clayey Soil and Its modified Alternatives (Case Study : Awunio – Lapuko National Road, Southeast Sulawesi)

“…Measure of infrastructure stability is determined by safety factor which compares resistance and load (Satrya et al, 2019). Therefore, CW must be designed to remain safe against overturning stability, slip stability and soil bearing capacity.…”

Correlation of Initial Soil Density and Maximum Soil Density Under Drying-Wetting Cycles and Their Soil Erodibility

“…During the design process, the stability of infrastructure is often assumed to be static and is considered by applying factors of safety generated by extreme condition analysis. Nevertheless, there has been a lack of consideration for the variability of natural factors, and notably, the growing risk posed by extreme environmental conditions resulting from global climate change (Satrya et al, 2019). At the construction of the serang-panimbang toll road, it is necessary to consider changes in soil characteristics in climate change in Indonesia.…”