Microstructures within and outside the smear zones for soft clay improvement using PVD only, Vacuum-PVD, Thermo-PVD and Thermo-Vacuum-PVD

Use of Microbially Induced Calcite Precipitation for Soil Improvement in Compacted Clays

“…Silica (Si), aluminium (Al), and lime (Ca) were found in all mixture samples. High Si, Al, and particularly Ca contents provide appropriate conditions for CaCO 3 formation, and higher ratios of Ca/(Si + Al) give higher potential for increasing the bond strength between clay particles [14][15][16][17]54]. In samples of C, CT, CVT, and CST after 7 days of curing, the weight percentage of Ca and ratio of Ca/(Si + Al) were 1.08, 13.45, 24.95, 34.89, and 0.03, 0.77, 1.58, 1.66%, respectively.…”

“…Various ground improvement methods have been successfully implemented on Bangkok Clay to make it suitable for geotechnical engineering projects, such as mechanical compaction, incorporating prefabricated vertical drains (PVD) [16,17], using cement and fly ash stabilisation [15,[18][19][20], utilising geosynthetics as a reinforcement layer [21,22], or applying controlled low-strength material (CLSM) as an alternative fill material [23][24][25]. Of these listed options, the mechanical techniques usually require specialised construction equipment that lead to high associated costs, while the chemical methods can increase the material's embodied energy and produce a large amount of carbon dioxide (CO 2 ) from hydration reactions, plus generate and release additional chemical toxicity into the ground during the implementation processes which lead to environmental concerns [26,27].…”

A Novel Approach to Determine the Treatment Range of Prefabricated Vertical Drains and Cement‐Soil Mixing Piles for Wide and High Embankment on Soft Ground

“…Hence, when the embankment on soft ground is high, it is necessary to pay more attention to the shear failure of soft ground (especially at the foot of slope) and enhance the treatment degree to adapt to the larger settlement of soft ground. The treatment methods for soft ground include replacement, riprap compaction, prefabricated vertical drains (PVDs), [13] deep soil mixing piles, cemented fly ash piles [14,15], and cementsoil mixing piles (CSMPs), et al Among them, the PVDs and CSMPs have been widely applied in embankment projects on soft ground [16][17][18][19][20][21][22][23] in recent years. PVDs mainly achieve the purpose of controlling the post-construction settlement by accelerating the dissipation of excess pore water pressure and increasing the settlement during the construction of the embankment.…”

“…The treatment methods for soft ground include replacement, riprap compaction, prefabricated vertical drains (PVDs), [ 13 ] deep soil mixing piles, cemented fly ash piles [ 14,15 ], and cement‐soil mixing piles (CSMPs), et al. Among them, the PVDs and CSMPs have been widely applied in embankment projects on soft ground [ 16–23 ] in recent years. PVDs mainly achieve the purpose of controlling the post‐construction settlement by accelerating the dissipation of excess pore water pressure and increasing the settlement during the construction of the embankment.…”