Page 20 - Building Regulation and Design Guidelines - Structural (Grey Code)
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SECTION: 1  GEOTECHNICAL GUIDELINES & REGULATIONS                                     SECTION: 1  GEOTECHNICAL GUIDELINES & REGULATIONS




                          •   Range of soil (particle size-sieve analysis) suitable for vibratory
                              techniques are zoned in Fig. (1.19) Indicating the best improvement           Stone Columns  Dynaminc Replacement  Controlled Modulus Coloumns
                              technique suitable for such soil. Fig. (1.20) Shows the most suitable            +
                              techniques for both cohesive and granular soils.                                Preload
                          •   The prices per cubic meters of the treated soil with respect to
                              depth for surface compaction, dynamic compaction and deep vibro
                              compaction are presented in Fig. (1.21) to ease the decision for the                                          +80-100 in
                              proposed improvement technique with respect to cost for granular             +25-36 in
                              soils                                                                                       COHESIVE SOILS: Clays, Sites, Peats
                                       Range of soils suitable for vibratory techniques
                             100%                                                                                                         Dynamic Compression
                              90%
                              80%
                              70%                                                                                                                      Compressive Soil
                              60%
                              50%
                              40%        D       C  B        A                                                           GRANULAR  SOILS: Gravel, Sand, Fill
                              30%
                              20%                                                                              Fig. (1.20): The Most Suitable Improvement Techniques for both
                              10%                                                                                         Cohesive and Granular soils
                               0%
                                0.001  0.01   0.1     1     10     100   1000
                                                Particle size (mm)
                                                                                                                                               Price per
                                                                                                                  0                            m 3  treated soil
                               Zone A: The soils of this zone are very well compactable.
                                                                                                                  2
                                     The right borderline indicates an empirically found limit
                                     where the amount of cobbles and boulders prevents                            4                         HEIC
                                     compaction because the vibroprobe cannot reach the                                                     (Impact Roller)
                                     compaction depth.                                                                                      DC
                                                                                                                  6                         (Weight Dropping)
                               Zone B: The soils in this zone are suited for Vibro Compaction.                                              Vibro Compaction
                                     They have a fines content of less than 10%.                                   8                         (Depth Vibrator)
                               Zone C: Compaction is only possible by adding suitable back-
                                     fill (Material from zones A or B) from the surface (stone                     10
                                     columns or sand columns).
                                                                                                                  Treatment
                                                                                                                  Depth [m]
                               Zone D: Stone columns are a solution for a foundation in these
                                     soils. There is a resulting increase in bearing capacity
                                     and reduction on total and differential                                    Fig. (1.21): Cost Comparison for the Different Improvement
                                                                                                                          Techniques  for Granular Soils
                                 Fig. (1.19): Range of Soils Suitable for Vibratory Techniques


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