---

In the last six decades, only a scant effort has been devoted to the reduction of heave forces acting on the upper part of lightly loaded or unloaded piles in swelling soils. For this purpose, an investigation site was established in Karmiel in Northern Israel. On this site twenty five unloaded piles were executed in a moderately expansive clay soil. Results obtained from pull out tests and from observations over a period of 30 months showed the following findings: Tensile resistance exists in the clay beneath the pile toe during the uplift test, the adhesion between the pile shaft and the surrounding clay is not only a function of the shaft roughness but a function of the pile diameter too, separating the piles from the surrounding clay in the active zone by a telescopic plastic sleeve reduced the vertical heave forces by 85% to 97% . In this way, several damages in buildings could be saved and bypassed. This book, therefore, provides a new casting method for reducing and, in some cases, eliminating vertical heave forces acting on piles in expansive clays.

---

Dr.Basem Hazzan is a postdoctoral research associate in Hazzan Foundation Engineering Company Ltd-Israel. He received a Ph.D. in Civil Engineering from the University of Wolverhmapton-U.K. His research includes an interesting solution for elimination of vertical heave forces acting on piles in swelling soils by coating them with a sleeve.

---