疎水性ポリイソシアネート系グラウトによる固結土の動的強度特性
1982 年 31 巻 341 号 p. 151-156
詳細
1982 年 31 巻 341 号 p. 151-156
Hydrophobic polyisocyanate grout is often applied in such places as subbases of railway tracks and roads, where dynamic loads predominate. Furthermore, dynamic loads will act on foundations of structures during earthquakes. In order to investigate the dynamic characteristics of soil solidified with hydrophobic polyisocyanate type grout (trade name is TACSS), the following studies were performed:
(1) Influence of repetitive stresses during early strength gain.
(2) High speed compression test.
(3) Behavior of the displacement under one million cycles of repetitive loads.
(4) Dynamic triaxial test to investigate the shear modulus and damping ratio.
The results obtained from these studies are as follows:
(1) There was no difference in compressive strength between the cases with and without repetitive stresses.
(2) When the loading speed was about 900 times of the normal speed, the compressive strength became 43% higher and the maximum strain was 28% less than the normal case.
(3) The solidified soil did not break even under one million cycles of repetitive loads whose stress amplitude was 10 to 90% of compressive strength.
(4) As the results of the dynamic triaxial test, 3000∼7000kg/cm2 of equivalent shear modulus (Geq) and 1∼10 of equivalent damping ratio (heq) were obtained, and they were independent of the repeated number (N).
These results show that the solidified soil (Toyoura standard sand) by TACSS looses the properties of sandy soil and exhibits the similar charcteristics of mud stone which has compressive strength of above 100kg/cm2.
