Geosynthetic Reinforcement in the Mitigation of Pipeline Flotation - Reinforced Soil Engineering: Advances in Research and Practice - page 237

Figure 5 Ground surface after pipe flotation.
Test 5. The soil cement was at an elevation 30 cm shallower than that of test
4. The pipe did not float until the excavation reached 20 cm below the
crown of the pipe. The soil cement block acted as an “anchor” and
offered a greater resistance to flotation.
5 FLOTATION
Figure 6 shows the flotation of pipe model and ground with time. The locations of
measurement points at the ground surface are shown in Fig. 2 . The two points
were at a distance 81 cm from the pipe center.
In tests 1 and 2, the movement of the ground surface was very little until the
pipeline floated. In test 3, with the presence of gravel, the ground surface was
affected when the pipe started to float gradually. In tests 4 and 5, the soil cement