(Generalized) 1. Select design wheel load based on most common, heaviest car and desired track speed. Consider all wheels in a truck and proximity of adjacent cars. 2. Select a Track Modulus, u or k, based on desired design deflection 3. Select rail size and section 4. Determine moment and loading coefficients 5.
In this model the subgrade soil assumes to behave like infinite number of linear elastic springs that the stiffness of the spring is named as the modulus of subgrade reaction. This modulus is dependant to some parameters like soil type, size, shape, depth and type of foundation and etc.
Oct 28, 2012· Are you saying that slab thicknes wont have impact on bending moment diagrams of the slab and necesray reinfrocement? RE: Subgrade modulus of soil geobdg (Geotechnical) ... (vertical or lateral subgrade modulus) by even 300% would do little .
Soil Compaction. Soil compaction is defined as the method of mechanically increasing the density of soil. In construction, this is a significant part of the building process. If performed improperly, settlement of the soil could occur and result in unnecessary maintenance costs or structure failure.
Other good subgrade practices are (CAPA, 2000 [3]; WAPA, 1995 [4]): Ensure the compacted subgrade is able to support construction traffic. If the subgrade ruts excessively under construction traffic it should be repaired before being paved over. Left unrepaired, subgrade ruts may reflectively cause premature pavement rutting.
Subgrade Reaction Modulus (K s) of Clayey Soils Based on Field Tests Figure 3 shows modulus of subgrade reaction versus unconfined compressive strength (qu). Therefore, with tabulated values proposed by Bowles [10] it can be converted into Figure 9 that is for modulus of subgrade reaction versus SPT values (N70).
use of this model is to determine the stiffness of elastic springs used to replace the soil below foundation. The problem becomes twofold since the numerical value of the coefficient of subgrade reaction not only depends on the nature of the subgrade, but also on the dimensions of the loaded area as well.
subgrade reaction are also likely to vary spatially, even for homogeneous soils. Thus, there is a need and scope ... Figure 1(b) provides the schematic diagram of the proposed problem. The granular strata are represented by Winkler medium and both the footing and the
Introduction. The subgrade modulus is not a fundamental soil property and its magnitude depends on many factors including the shape of the foundation, the stiffness of the foundation slab, the shape of the loading on the foundation, the depth of the loaded area below the ground surface, and the time.
One particular example is the pavement. The occurrence of damage to road founded on unsaturated subgrade in Karak, Jordan is due to the collapse of the soil structure upon wettingwetting process, has come to be well recognized.
Expansive Soils. Other methods include foundation removal and replacement with structural concrete or posttension concrete slabs, installation of concrete cutoff walls, underpinning, subgrade irrigation, treatment of the soils with chemical admixtures, or the construction of French drain systems.
A STUDY ON THE CHARACTERISTICS OF DYNAMIC HORIZONTAL SUBGRADE REACTION FOR DIFFERENT TYPES OF GROUND BY ... the characteristics of dynamic horizontal subgrade reaction during earthquakes, including nonlinearity and other complex factors, must be ... Figure 1 also shows a conceptual diagram of the models. For analysis, it was assumed that the ...
Evaluation of Subgrade Stabilization on Pavement Performance Louisiana Transportation Research Center Mark Morvant, Pavement Geotechnical Research Administrator. Lime Treated Working Table. Subgrade Dry Embankment Subgrade Existing Subgrade ... l Silt subgrade test sections PI<11
A 3D traintracksubgrade interaction finite element (FE) model was constructed using the ABAQUS code, where different vertical irregular track spectra were simulated by modifying the vertical node coordinates of the FE mesh of the rail. ... A schematic diagram of the train model is illustrated in Figure 2(a). The train carriage, train bogies ...
In the other two models, the loose sandy subgrade was stabilized with DMCs (with 10 cm diameter, 40 cm length, and 25 cm centertocenter spacing) in triangular and square patterns, respectively. Then, after 28 days, the embankment was constructed over the .
Fig. shows the cross section diagram for existing line without widening the subgrade. To build the second line, for the shoulder width of the existing subgrade, the general embankment is not less than m, and the cutting is not less than m. In a difficult segment, the embankment is less than m.
In performing construction surveying, preparation is a major part of the operation. Study the contract plans, special provisions, Standard Plans, Standard Specifications, the ... a ground shot at the subgrade shoulder distance (SGS), subtract the rod readings. The ... Construction Survey Procedures
Using the E values, modulus of subgrade reaction can be calculated and vice versa as well. ... Evaluation of Modulus of Elasticity and Modulus of Subgrade Reaction of Soils Using CBR Test ... Elsa Eka Putri, N. Kameswara Rao, M. A. Mannan, Evaluation of Modulus of Elasticity and Modulus of Subgrade Reaction of Soils Using CBR Test, Journal ...
Subgrade materials are typically characterized by (1) their resistance to deformation under load, in other words, their stiffness or (2) their bearing capacity, in other words, their strength. In general, the more resistant to deformation a subgrade is, the more load
The field Plate Load Test is commonly used to predict the deformations and failure characteristics of the soil/subgrade and modulus of subgrade reaction (ks). The Modulus of subgrade reaction (ks) is used in foundation design, soilstructure interaction studies and design of highway pavements.
Subgrade Waterproofing Retrofit Performancebased waterproofing specifications may require a watertight subgrade interior space, but may not accurately represent the existing conditions. The extent of material deterioration, changes in ground water conditions and other factors can drastically affect the scope of retrofit waterproofing repairs.
Effect of subgrade strength on the contributory Cc coefficient of curvature of the sand performance of only geocell reinforcement with a height (h) (dimensionless) of for different levels of settlements (s/D%) cu undrained shear strength of clay (Pa) Geosynthetics International, 2013, 20, No. 6 Influence of subgrade strength on the ...
on top of the subgrade soil, whereas in the second set a subbase was placed between the slab and the subgrade. By using either maximum stress or maximum deflection at the surface of slab as parameter for comparison, an equivalent kvalue on the subbase could be obtained.
