Jet grouting for mitigation of installation disturbance

Abstract

To reduce the impact of installation of horizontal jet grouting columns on surrounding ground, a new horizontal jet grouting technique termed controlled discharge horizontal jet grouting is developed. A field trial programme is conducted to verify the application of the technique technology. Field measurements of ground surface displacement and induced excess pore-water pressures are obtained during implementation of the technique. Five trial jet grout columns are installed at 2 m below the ground surface and subsequently exposed for measuring and testing. The observed vertical displacements of the ground surface range from 0 . 4 to 9 . 4 mm, with maximum excess pore-water pressures generated during the field trial varying between 3 . 5 and 25 . 6 kPa. The diameters of the exposed jet grout columns range from 1 . 1 to 1 . 4 m. Core samples extracted from the trial jet grout columns indicate that the quality of the jet-grouted soil formed is good, with total core recovery of 70-95% and rock quality designation of 79-92%.Unconfined compressive strength tests show that the 28-d strength ranges from 0 . 9 to 1 . 5 MPa, and Young's modulus at 50% failure load (E 50 ) is between 61 . 5 and 145 . 3 MPa. The field trial results confirm the applicability of the technique for achieving low-impact installation of horizontal jet grouting.

Laboratory evaluation on the effectiveness of polypropylene fibers on the strength of fiber-reinforced and cement-stabilized Shanghai soft clay

“…deep mixing columns (Shen et al, 2003a(Shen et al, ,b, 2008, jet grouting columns (Shen et al, 2013a,b;Wang et al, 2013Wang et al, , 2014 and shallow ground to be used as subgrade of road (Shen et al, 2007). However, some traditional techniques are significantly expensive and impractical.…”

Clay Grouting Mechanisms and Applications

“…The shear strength of the soft soil deposits due to the water contents close to their liquid limits is very low, leading to an inability of supporting upper buildings and/or structures [3][4][5][6][7]. To tackle this key engineering issue, grouting technologies have been widely adopted to improve the mechanical properties of the soft soil deposits [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Notwithstanding that, the effectiveness of grouting in such geological conditions can be significantly affected by the configuration of grouting programme.…”

Sustainable Measures for Mitigation of Flooding Hazards: A Case Study in Shanghai, China

“…The Huangpu River, a tributary of the Yangtze River, runs through Shanghai. Figure 1 presents a schematic of the Shanghai administrative region [19][20][21][22][23]. The annual rainfall is approximately 1200 mm, of which 60% falls during the flooding season from May to September [24][25][26][27].…”