Investigation of Natural Beachrock and Physical–Mechanical Comparison with Artificial Beachrock Induced by MICP as a Protective Measure against Beach Erosion at Yogyakarta, Indonesia

Abstract

Typically, the mitigation of coastal erosion is achieved by amending surface conditions using materials, such as concrete. The objective of this study is to evaluate the feasibility of constructing artificial beachrocks using natural materials (e.g., microbes, sand, shell, pieces of coral, and seaweed, etc.) within a short time, and to propose the method as a novel strategy for coastal protection. Initially, a survey on resistivity and a multichannel analysis of seismic waves (MASW) were conducted along the coastal lines to characterize and elucidate the subsurface structure of existing beachrocks in the Southeast Yogyakarta coastal area, Krakal-Sadranan beach, Indonesia. The field survey on natural beachrocks suggested that both resistivity and shear wave velocity were higher in the deeper deposits compared to the underlying unconsolidated sand layer within a depth of approximately 1.5 m and covering an area of 210.496 m 2 for the α-section and 76.936 m 2 for the β-section of beachrock deposit. The results of the sand solidification test in the laboratory showed that treated sand achieved unconfined compressive strength of up to around 6 MPa, determined after a treatment period of 14 days under optimum conditions.

Bio‐mediated soil improvement: An introspection into processes, materials, characterization and applications

“…Alternatively, the creation of artificial beachrocks using natural materials (e.g. microbes, sand, shell, pieces of coral and seaweed) within a short time by MICP method was a milder approach (Daryono et al, 2020; Imran et al, 2019).…”

Experimental Study on Sand Stabilization Using Bio-Cementation with Wastepaper Fiber Integration

“…Based on multidisciplinary research, MICP refers to utilizing microorganism function to induce the carbonate from urea to precipitate in the presence of calcium ions, filling the space in soils and bonding the loose particles to achieve Inspired by a natural phenomenon of microbial mineralization, applications of MICP have been expanding into a broader range over the past two decades. For instance, it can be an alternative to rigid structures using concrete for coastal erosion mitigation in the marine environment [8][9][10]. In terms of the construction industry, this technique is proved to have a promising future to be applied in soil improvement [11], liquefaction prevention [12], road construction [13], and slope stabilization [14].…”

“…Inspired by a natural phenomenon of microbial mineralization, applications of MICP have been expanding into a broader range over the past two decades. For instance, it can be an alternative to rigid structures using concrete for coastal erosion mitigation in the marine environment [ 8 , 9 , 10 ]. In terms of the construction industry, this technique is proved to have a promising future to be applied in soil improvement [ 11 ], liquefaction prevention [ 12 ], road construction [ 13 ], and slope stabilization [ 14 ].…”

Biocementation of Calcareous Beach Sand Using Enzymatic Calcium Carbonate Precipitation

“…Despite many studies on using microbially induced calcite precipitation MICP and EICP for soil improvement, there are only a few MICP studies using this technique for the treatment of beach sand [16][17][18][19][20][21][22][23]. Shanahan and Montoya [16] created a bench model simulating a coastal sand dune using a clean fine sand, typical of coastal dune deposits.…”

“…The angle of repose of the treated sand increased remarkably as well. Daryono et al [22] studied the feasibility of constructing artificial beach rocks using MICP and beach sand as a proposed method for coastal protection against water erosion. The results indicated that artificial bedrocks have an unconfined compressive strength of up to around six MPa.…”