Experimental study on grouting in underconsolidated soil to control excessive settlement

Abstract

The underconsolidated soils in reclaimed land have low strength and high compressibility, resulting in susceptibility to excessive settlement and associated negative effects, which can be controlled by grouting. However, there is little research on the mechanism of grouting in underconsolidated soil, compared with the normally consolidated or overconsolidated soil. In this study, we present a series of laboratory grouting tests to investigate the grouting mechanism and the effect of degree of consolidation, soil type, load increment ratio and initial overlying load on the grouting performance. The results showed that the influence of grouting on primary consolidation settlement for underconsolidated soil included the heave effect, the additional settlement due to the dissipation of excess pore water pressure induced by grouting and the reduced settlement due to the increased modulus induced by grouting. However, grouting in underconsolidated soil had no influence on the secondary consolidation settlement. Grouting in underconsolidated soil with low degree of consolidation could obtain a shorter time of primary consolidation and a higher final grouting efficiency in primary consolidation stage. The final grouting efficiency in primary consolidation stage increased linearly with increasing load increment ratio, but decreased with increasing initial overlying load. As the overconsolidation ratio increased, the final grouting efficiency in primary consolidation stage decreased for underconsolidated soil, dropping to the lowest value for normally consolidated soil and then increased for the overconsolidated soil, reaching a limit. Moreover, the peak grouting pressure was proportional to the vertical effective stress at the beginning of grouting.

Marl Soil Improvement Using Recycled Concrete Aggregates From Concrete Pipes Factory

“…Binder stabilization is beneficial for both cohesive and granular soils (Chen et al, 2020), whereas for weak or loose soils, reinforcement stabilization is frequently used to reduce soil movement, erosion, or slope failure (Aga, 2021). On the other hand, grouting is a more common technique for loose or unconsolidated soils despite having higher costs (Zheng et al, 2016). In addition to being technically advantageous, using RCA to stabilize marl soil benefits both the environment and the economy because it is readily available, does not need to be extracted or processed again in order to be recycled or reproduced, and is relatively inexpensive.…”

Calculation of the foundation settlement during compensation grouting

“…When building a finite element model, the heterogeneity of the site's geotechnical conditions, the spatial rigidity of the building and the phasing of the tunnel under the building were taken into account. [8][9] To take into account the phasing and more correctly calculate the volume of the suspension during compensation grouting, the tunnel was divided into 11 parts. The calculation was carried out in several stages, with the sequential switching on of the next grab of the tunnel and compensation grouting to level the deposit of the building above it.…”

Cement Grout Nonlinear Flow Behavior through the Rough-Walled Fractures: An Experimental Study

“…Fractured rock masses (Figure 1(a)) are widely distributed in underground engineering due to geological action or excavation disturbance, which may bring serious safety hazard to the engineering stability [1][2][3][4]. Grouting is a useful way for controlling groundwater inrush and improving mechanical properties of fractured rocks in underground mining and engineering [5][6][7][8][9]. In order to acquire a better understanding of the grouting mechanism of fractured rock, lots of experimental studies have been performed in recent decades.…”