A field trial of jet-grouting in marine clay

2001 ◽  
Vol 38 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Teoh Yaw Poh ◽  
Ing Hieng Wong
Keyword(s):  
Ground Improvement ◽  
Free Field ◽  
Earth Pressure ◽  
Soil Mass ◽  
Diaphragm Wall ◽  
Marine Clay ◽  
Jet Grouting ◽  
Strength And Deformation ◽  
Diaphragm Walls ◽  
Soil Movements

The basement excavation of the Singapore Post Center involved extensive jet-grouting to improve the soft marine clay present within the excavation. The treated soil mass, with much improved strength and deformation characteristics, was intended to act as an internal strut below the bottom of the excavation level, reducing movements caused by the basement excavation. This paper presents the performance of a well-instrumented field jet-grouting trial during the construction of the building basement. Results of monitoring suggest that the jet-grouting trial caused the retaining diaphragm walls and the adjacent soils immediately behind and at some distance away from the walls to move away from the jet-grouted area. The maximum free field lateral soil movements in the excavation side of the jet-grouted mass were much larger than the corresponding lateral movements behind the wall. The results suggest that the diaphragm wall provided considerable restraint, thereby reducing the lateral movements of the soil behind the wall induced by the jet-grouting. Bending moments were induced in the diaphragm walls due to the jet-grouting work. The jet-grouting also caused some increase in the lateral earth pressure and the piezometric levels.Key words: jet-grouting, ground improvement, diaphragm wall, ground movements.

scholarly journals Experimental and Numerical Investigation on the Effects of Foundation Pit Excavation on Adjacent Tunnels in Soft Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zi-Tian Yu ◽  
Heng-Yu Wang ◽  
Wenjun Wang ◽  
Dao-Sheng Ling ◽  
Xue-Dong Zhang ◽  
...  
Keyword(s):  
Retaining Wall ◽  
Soft Soil ◽  
Shear Bands ◽  
Earth Pressure ◽  
Bending Moment ◽  
Surface Settlement ◽  
Diaphragm Wall ◽  
Foundation Pit ◽  
Obvious Effect ◽  
Diaphragm Walls

Excavations near an existing tunnel are often encountered in underground construction. The influence of the excavation on the adjacent tunnels is not yet fully understood. This study presented a centrifugal model test about excavation next to existing tunnels in soft soil foundation. The bending moment of diaphragm wall, surface settlement, tunnel deformation, and earth pressure around the tunnel were mainly studied. The influence of tunnel location is further studied by numerical simulation. During the stabilization stage of foundation pit, the diaphragm walls present convex deformation towards foundation pit, and the surface settlement outside the diaphragm wall appears to be the concave groove type. During the overexcavation stage, the diaphragm walls are almost damaged, and the shear bands are nearly tangent to the tunnels. The displacement of the tunnels and the surface settlement rapidly increase. The deformation of the diaphragm wall and the surface settlement are limited by the existing tunnel. The numerical results indicate that the change of tunnel location has little effect on the retaining wall but an obvious effect on the tunnel itself.

Ground Improvement Design and Construction for Seattle's Elliott Bay Seawall Replacement and Retrofit

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
William Perkins
Keyword(s):  
Seismic Vulnerability ◽  
Ground Improvement ◽  
Soil Mass ◽  
Lessons Learned ◽  
Performance Criteria ◽  
Earthquake Ground Motion ◽  
Significant Deterioration ◽  
Soil Cement ◽  
Jet Grouting ◽  
Space Requirements

The Elliott Bay Seawall in Seattle, Washington, was constructed in the early 1900s over soft/loose non-engineered and liquefaction susceptible fill, estuary, and beach deposits. The fill includes wood from historic waterfront sawmills and debris from the 1889 Great Seattle Fire. After the 2001 Nisqually earthquake, an evaluation of the seawall condition and seismic vulnerability determined that it had undergone significant deterioration and was susceptible to collapse for a 100-year earthquake. This evaluation led to design and replacement/retrofit of 1,130 meters (3,700 feet) of seawall. The new seawall includes an improved soil mass constructed of a cellular arrangement of jet-grout columns that supports a seawall superstructure and provides all seismic lateral restraint. The improved soil mass seismic performance criteria are based on allowable seawall displacement for three earthquake ground motion levels. Final improved soil mass design utilized non-linear dynamic soil-structure interaction analyses. To meet performance criteria, improved soil mass widths range between 7.9 and 18.3 meters (26 and 60 feet), ground improvement area replacement ranges between 50 and 64 percent, and jet-grout soil-cement unconfined compressive strength ranges between 0.86 and 2.76 MPa (125 and 400 psi), depending on the soil type. Improved soil mass construction issues included equipment selection, limited space, spoils handling, wood debris, and obstructions (e.g., buried utilities, piles, and temporary shoring). Lessons learned included: (1) jet grouting was the best construction method given the utilities and thousands of piles beneath the site, (2) early obstructions identification and contingency plans are critical to maintain production, and (3) an understanding of space requirements for all construction activities is required for safe and productive working conditions.

Ground Improvement. Recycle of Construction Sludge in Soil-Cement Diaphragm Walls.

2000 ◽  
Vol 49 (1) ◽  
pp. 46-49
Author(s):  
Takeo SUZUKI ◽  
Toshimitsu KUNITO ◽  
Motohiro NISHI
Keyword(s):  
Ground Improvement ◽  
Soil Cement ◽  
Diaphragm Walls

scholarly journals Numerical Analysis on Performance of the Middle-Pressure Jet Grouting Method for Ground Improvement

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 313
Author(s):  
Shinya Inazumi ◽  
Sudip Shakya ◽  
Takahiro Komaki ◽  
Yasuharu Nakanishi
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Ground Improvement ◽  
Cement Slurry ◽  
Mechanical Agitation ◽  
High Quality ◽  
Jet Grouting ◽  
Computer Aided ◽  
Improvement Method ◽  
Cae System

This study focused on the middle-pressure jet grouting method, which has a complicated development mechanism for the columnar soil-improved body, with the aim of establishing a computer-aided engineering (CAE) system that can simulate the performance on a computer. Furthermore, in order to confirm the effect of middle-pressure jet grouting with mechanical agitation and mixing, a comparative analysis was performed with different jet pressures, the development situation was visualized, and the performance of this method was evaluated. The results of MPS-CAE as one of the CAE systems showed that the cement slurry jet ratio in the planned improvement range, including the periphery of the mixing blade, by the middle-pressure jet grouting together with the mechanical agitation and mixing was increased and a high quality columnar soil-improved body was obtained. It is expected that the introduction of CAE will contribute to the visualization of the ground, and that CAE will be an effective tool for the visual management of construction for ground improvement and the maintenance of improved grounds during the life cycle of the ground-improvement method.

Uplift and Settlement Prediction Model of Marine Clay Soil e Integrated with Polyurethane Foam

2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Clay Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Effective Thickness ◽  
Marine Clay ◽  
Uplift Pressure ◽  
Pu Foam ◽  
Improvement Method

AbstractPolyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.

Earth Pressure on Caissons in Marine Clay Under Cyclic Loading

2007 ◽  
Vol 25 (1) ◽  
pp. 15-35 ◽  
Author(s):  
S. Narasimha Rao ◽  
N. Darga Kumar
Keyword(s):  
Cyclic Loading ◽  
Earth Pressure ◽  
Marine Clay

Reliability analysis of drilled piers in expansive soils

1991 ◽  
Vol 28 (6) ◽  
pp. 834-842 ◽  
Author(s):  
Carlos Ferregut ◽  
Miguel Picornell
Keyword(s):  
Probabilistic Models ◽  
Load Transfer ◽  
Expansive Soils ◽  
Free Field ◽  
Expansive Soil ◽  
Maximum Tensile Stress ◽  
Limit States ◽  
Tensile Stresses ◽  
Head Displacement ◽  
Soil Movements

Heavy structures in areas with expansive soils are commonly founded on piers resting beneath the surface active zone. During construction, the piers remain essentially unloaded and are exposed to potentially high tensile stresses that can split the pier unless the pier has been adequately reinforced. In this context, uncertainties arise relative to (i) the parameters governing the load transfer from the soil to the pier, (ii) the potential heave to be expected in a "free field" condition, when the soil movements are not restricted by the pier, and (iii) the estimation of the pier capacity to resist the induced stresses. Probabilistic models to handle and to quantify these uncertain parameters are constructed and then used to compute the probability of exceeding two potential limit states: (i) vertical pier head displacement and (ii) maximum tensile stress in a cross section of the pier. The displacements are used to assess the serviceability performance of the pier, and the maximum tensile stresses are used to estimate the reliability of the pier. Key words: piers, expansive soil, reliability, probability, foundations.

Jet-Grouting in Cohesive Soils for Ground Improvement in Hawaii

GeoRisk 2011 ◽  
2011 ◽  
Author(s):  
John Y. L. Chen ◽  
Robin M. Lim ◽  
Kyle Furuhashi
Keyword(s):  
Ground Improvement ◽  
Cohesive Soils ◽  
Jet Grouting
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