Cassagrande proposed an empirical construction to obtain from the (e – log ') curve for an over-consolidation clay, the maximum effective vertical stress that has been acted on the clay in past referred to as the pre-consolidation pressure ( 'c), and the overburden pressure ( 'o) is the vertical effective stress acting at any specific ...Web

Consolidation of clay, with special reference to influence of vertical sand drains : a study made in connection with full-scale investigations at Skå-Edeby | Semantic Scholar. …Web

H is the thickness of the clay layer; q 0 is the instantaneous uniformly distributed load applied on the top surface of the clay layer; v depicts the seepage velocity; z and z 0 represent the downward vertical coordinate originated from the top boundary and the depth of soil unit, respectively. In Hansbo's flow, the relationship between ...Web

A rigorous solution for the consolidation of soil by displacement-type vertical drains with finite permeability is presented taking into account the disturbance in a clay ring surrounding the drain pile caused by drain installation. The accuracy of both Barron's and Hansbo's approximate solutions regarding well resistance and smear is ...Web

The total vertical stress at the pre-consolidation pressure, for these specimens, is in the order of (sigma _mat{{v}}=105) kPa. For the Series 2 clay specimens, which were retrieved at a depth in a range of 5.66 to 5.79 m, the total vertical stress is in the order of (sigma _mat{{v}}=133) kPa. A similar observation is carried …Web

Among different ground improvement options, strengthening of soft clay by vertical drains with preloading is the best option and is preferred by engineers (Sarika S, Deepankar C, Salunkhe JS (2015) Ground improvement of marine clay for highway construction at Mumbai, India. ... The rate of vertical consolidation is insignificant on …Web

where T v is the time factor depending on the degree of consolidation, d is the drainage path, in the following case study it is taken as 9.5 m, which is equal to the clay layer thickness, and C v is the coefficient of vertical consolidation C v. The time without ground improvement was 95 years.Web

Figure 4 shows variation in the undrained strength ratio with vertical consolidation stress. The undrained strength ratio varies between 0.18 and 0.42, which is much larger than the actual value range …Web

A normally consolidated clay layer is 6.0 m thick and is drained along one boundary. Following the application of an applied load, the ultimate primary consolidation …Web

maximum past vertical effective stress per Se. The concept of a maximum past pressure P. based on changes in the compressibility of the clay is shown in Figure 1. Vertical strain €, is plotted versus consolidation stress ' for 1-dimensional compression of a hypothetical clay with an in situ stress p equal to 500 lb/ft2 (23.9 kPa).Web

Land subsidence is an important environmental problem in the North China Plain (NCP). A typical subsidence area mainly located on adjoining areas of Beijing and Hebei provinces was selected to study the consolidation characteristics of deep clayey soil. Clay samples were collected from 14 boreholes at different depths, and the compression …Web

where σ'p is the maximum past pressure, σ'vf is the final vertical effective stress at the end of consolidation, ∆εv is the vertical strain, and e0, σ'vi are the initial void ratio and vertical effective stress. Cc and Cr are the compression and recompression indices, respectively and represent the slopes of the compressionWeb

Consolidation settlement of pile groups is computed using the following simplified assumptions: 1. Assume the pile group to be a solid foundation with a depth of 2/3 the length of piles. 2. Effective stress at midpoint of the clay layer is used to compute settlement. 3. Consolidation equation.Web

Fig 10.2 Vertical stress changes during consolidation The stress changes throughout the depth of a soil layer in a one dimensional field situation are ... shown in Fig. 10.5., in …Web

A one-dimensional consolidation test is performed on an undisturbed sample of clay and the following results are obtained: Effective Vertical Stress (kPa) Void Ratio Void Ratio 20 Effective Vertical Stress (kPa) 640 1280 320 80 40 0953 0.945 0.937 0.927 0.889 80 160 320 0.789 0.691 0.708 0.722 0.738 20 (a.)Web

"Consolidation theory of unsaturated soils with vertical drains considering well resistance and smear effect under time-dependent loading." J. Eng. Mech. 147 (9): …Web

consolidation of saturated clay subjected to external load ∆σ . The springs and the surrounding water represent the saturated soil. The springs ... In this arrangement the compression is one dimensional and flow will be in the vertical direction. When pressure ∆σ is applied this will be borne by water surrounding the springWeb

The coefficient of vertical consolidation, c v, of the kaolin clay was derived from Rowe Cell data reported in Richardson et al. (2009), which shows c v to be a function of vertical effective stress level, varying from 1.4 m 2 /yr at σ′ v = 20 kPa (i.e. at a sample depth of ~1B) to around 3.4 m 2 /yr at σ′ v = 73 kPa (i.e. at a sample ...Web

Consolidation of soil (normally consolidated) can be evaluated from the following equation as discussed in this article. S c = C c H c /(1+e 0) log[(σ' 0 +Δσ' av)/σ' 0]. Where. S c – consolidation settlement in the normally consolidated clay. C c – Compression index – to be evaluated from the laboratory testing. H c – Height of the clay …Web

Question: A laboratory consolidation test was performed with doubledrainage on a normally consolidated (NC) clay sample extracted from a soil profile at a construction site. The following details are known:Initial vertical effective stress σ'?2=200kPa initial voidratio e0=1.0Final vertical effective stress σV'=400kPa and e=0.8 at theend of …Web

Ground improvement is a complex issue, and accurately predicting the consolidation and settlement of soft soil with prefabricated vertical drain (PVD) …Web

Likewise, the reinforced clay mass settles more rapidly than the untreated one as the provision of drains perpetuates consolidation process. The soft clay undergoes a consolidation settlement of 0.272 m in the presence of SVD within 244 days whereas a vertical deformation of 0.261 m is observed within 376 days of consolidation period in …Web

Application of vertical drains in soft clay soils is a common practice widely known to facilitate the consolidation rate. To overcome the adverse impact of a long …Web

clay Figure 8. Typical plot of soil soil Profile properties versus depth. Figure 9. Typical curve of time versus settlement: parabolic to R00 J Time t. min llog saab)- Figure 10. Typical curve of void ratio versus effective vertical stress. Figure 11. Relation between settlement ratio and over-consolidation ratio. Overconsolidation Ratio, Pr/p; 'LiWeb

This paper presents a model to describe the above important phenomena during the consolidation of sensitive clay with vertical drain. The solution for proposed model can be obtained by extending the closed-form solution of the consolidation of double-layered ground with vertical drain by the interactive method introducing the …Web

This paper investigated the large-strain consolidation of soft clay with vertical drains under free-strain theory, considering the elastic viscoplastic constitutive relation of soft soil, the coupled vertical–radial non-Darcian flow, and the logarithmic relationship of the permeability coefficients. Meanwhile, the nonideal cylindrical unit ...Web

If $300-mat{mm}$ diameter sand drains at $4 mat{~m}$ centres in a square pattern were installed in the clay, in what time would the same overall degree of consolidation be reached? The coefficients of consolidation in the vertical and horizontal directions, respectively, are $9.6$ and $14.0 mat{~m}^{2} /$ year.Web

are equal to (20m) and (50m), respectively, so that, the side slope horizontal: vertical is equal to (1:3). The depth of the soft clayey soil layer is equal to (5m). The water table level at the surface of the soft clay layer. Figure 4. Schematic of the geometry of the embankment and softy clay layerWeb

To some extent, it indicates that the vertical drainage capacity of clay plays an increasingly important role in the consolidation settlement of newly formed land …Web

This paper presents a model to describe the above important phenomena during the consolidation of sensitive clay with vertical drain. The solution for proposed model can be obtained by extending the closed-form solution of the consolidation of …Web

To speed up the primary consolidation of the plastic clay, vertical wick drains ( r w = 32 mm, triangular pattern) with a spacing of 1.5 m are installed penetrating to the top of the sand layer. Ignore the smear effect. Compute settlement of the ground surface after one year and 50 years.Web

Consolidation of inhomogeneous clay with a system of horizontal and vertical drains is considered. Horizontal drains in the system are made of multiple thin …Web

Fig 10.2 Vertical stress changes during consolidation The stress changes throughout the depth of a soil layer in a one dimensional field situation are ... shown in Fig. 10.5., in which a compressible clay is sandwiched between two relatively incompressible sand layers, the water table being at the ground surface. ...Web