Horizontal deformations

Horizontal deformations of the reclamation fill are seldom or never specified as a project requirement. It is generally accepted that a stable structure, which is designed with an adequate safety factor, will experience limited horizontal deformations. 

Simple methods to calculate horizontal deformations do not exist. Finite Element Methods (FEM) or the theory of a beam on an elastic subgrade (e.g. sheet-pile design), are normally used for an analysis of horizontal displacements. 

Measurement of horizontal deformations can be realised by means of inclinometers (see Section 11.3.3.2 on monitoring) which are generally used to verify the stability of a slope or a retaining structure. 

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The stiffness modulus is a fimction of load, stress, horizontal deformation, percentage of bitumen and poisson ratio. The Poisson ratio s normally assumed to be 0.35 which is a representative value for most asphalt. 

Observations demonstrated that bonding of concrete slabs with polymer PM reduces vertical and horizontal deformations of them of about 50%, allowing for safe work of airfield pavements. It should be noticed that contractions joints deform horizontally of about 5 mm between winter and summer and similar value was measured in cases of vertical deformation. An example of 24 hours measurements of vertical displacements of airfield slab is presented in Fig. 16 (for original slab with bituminous filling and slab bonded with polymer PM). Comparison of vertical displacement shows that the use of polymer joints in contradiction to bituminous mass reduces warping deformations of the comers about two times, what is very advantageous in aspect of airfield exploitation. 

Figure 3 Horizontal deformation of the central point 4c versus time...

Henneberg H. 1978b Measurements of vertical and horizontal deformation components in the petroleum area of Maracaibo. 2nd Intern. Symp. of Deformation Measurements with Geodetic Methods, Bonn. 

According to CEN EN 12697-26 (2012), the rise time is fixed to 124 4 ms. The peak load is adjusted to achieve a target peak transient horizontal deformation of 0.005% of the specimen diameter. Experience dictates that the suitable values of peak horizontal deformation are 5 2 microstrain (10" m/m) for a 100 mm diameter specimen and 7 2 microstrain (10 m/m) for a 150 mm diameter specimen. The pulse repetition period is 3.0 4 s. 

After the conditioning load pulses, five more load pulses are applied, during which the applied load and the resulting horizontal deformation are recorded. For each load pulse, the stiffness modulus is determined using the following equation ... 

The cylindrical specimen is placed into the steel load frame of the testing device, similar to the one used in the indirect tensile test. The measurement of horizontal deformation can be carried out by load transducers (linear variable displacement transducers [LVDTs]), with an arrangement similar to Figure 7.2, or by strain gauges with extensometers (see Figure 7.3). 

Particularly, although the repetitive compressive load applied is a haversine and is applied along the vertical diametral plane of a specimen, the resilient Poisson ratio, p, is first calculated using the recoverable vertical and horizontal deformations, and subsequently two separate resilient moduli, Mr, are determined the instantaneous resilient modulus and the total resilient modulus. 

In the EN indirect tensile test, the amplitude of the horizontal deformation obtained during load cycle is used for the determination of the modulus called stiffness, E. 

The specimen is positioned in the loading device so that the axis of the deformation strips is 90° 5° to the axis of loading strips. During the test, the load and the resulting horizontal deformation are recorded at pre-selected intervals (number of loadings). A schematic representation of the test device is given in Figure 7.30. 

After the test temperature has been reached, the specimen is subjected to a static load, without impact, that produces a horizontal deformation of 0.00125 to 0.0190 mm, for a period of 100 s. 

Dx - horizontal deformation, displacement in the direction of the force D(p - deformation due to rotation of the base around the neutral axis... 

Chfai s research results showed that the ratio of the maximum horizontal deformation of deep and settlement of embankment can reflect the stability of the embankment, and he recommended the ratio cannot exceed 0.5 (Chfai et al. 2002). Figures 6 and 10 showed that the ratio was 0.28 when filling height was 2.4 m, and the ratio was... 

Figure 4.12 Schematic structure of cordierite. Thermal expansion occurs predominantly in the a-plane. A horizontal deformation of the charge fields of the oxygen anions causes contraction in the c-direction.

Stiffness of fill mass Settlements, horizontal deformations and tolerances... 

The deformations of a fill mass are often governed by the stiffness of the subsoil. In partieular the presenee of a soft, cohesive subsoil below the fill may cause not only long term eonsolidation settlements of the fill surfaee, but also horizontal deformations near the edges of the fill mass. These deformations may adversely affect the integrity of struetures built on or in the immediate vieinity of the fill mass. 

The instantaneous settlement is a result of a horizontal deformation. The volume of the soil remains unchanged. This kind of deformation is often modelled using the elastic theory. For large reclamation areas, this definition of instantaneous settlement can be neglected since there will be no horizontal deformation. 

However, in the design of quay walls or sheet-pile struetures, horizontal deformations can be an issue and the stresses introduced by fill material deposited behind the structure should be taken into account. This also applies for temporary conditions, for instance, during staged filling operations (Figure 8.25). 

Some specific situations need special attention when realising a hydraulic fill project for land reclamation. Horizontal deformations may have a detrimental effect on existing neighbouring structures, specifically if they are founded on deep foundations which are quite vulnerable for such type of loading conditions (Figure 8.42). 

Allowable residual settlements and horizontal deformations. These are defined by the stiffness of the fill mass (and subsoil) and the design of the superstructures and infrastructure. 

Analysis and Design Issues of Geotechnical Systems Flexible Walls, Fig. 11 Noimalized peak horizontal deformations distribution along height of wall facing (Halabian et al. 2010) (a) Normalized peak horizontal displacement (b) Normalized peak horizontal displacement... 

Figure 36 indicates a water pipeline after extensive liquefaction caused by the 1990 Luzon earthquake of surface-wave magnitude = 7.8. The buckling of this pipeline was caused by compressional deformation of the local subsoil. Whether compression or extension, the horizontal deformation and displacement of liquefied ground exert serious effects on underground structures. Hamada et al. (1986) found a... 

As shown in Fig. 16.2, strains e, which correspond directly to the mobilized forces and thus the efficiency of the two layers, are significantly different. For the bottom layer the maximum strain in the reinforcement is 7.5%, whereas for the upper one (0.5 m above) it measures 4.1%. Consequently, the bottom layer tends to be overstressed because of the undastressing (not full mobilization) of the upper one. The corresponding stress ratio which is the mobilized tensile force—UTS is about 60% for the bottom layer (a high value) and about only 30% for the upper layer (Blume et al., 2004). Despite the huge settlement of the embankment, vertical and horizontal deformations in the critical zone adjacent to the railroad remained in the range of some millimeters over the whole construction period and after more than a year of final consolidation, until September 2005. 

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