Test on Mechanical Properties of Cemented Soils Using Secondary Development Data Acquisition Test System
A secondary development of computer aided data acquisition test system is performed in order to improve the disadvantages of original system. In this way, the qualified influences of cement content and curing time on yield strength and stiffness of soil can be automatic acquisition in consolidated undrained triaxial tests. The data collected from the system show that the deviatoric stress of soil increases with increasing axial strain initially followed by a relatively smooth decline after yield point. Yield strength increases with increasing cement content and curing time at the same strain. A well-defined linear relationship between yield strength and cement content are observed and also the relationship between yield strength and curing time. Finally, a linear function is defined to express the linear relationship between yield strength and those two factors and corresponding linear coefficients are obtained through a multiple regression analysis of test data. Stiffness of specimens shows an initial sharp degradation followed by smooth attenuation with increasing axial strain. The addition of cement and long curing time can effectively improve the stiffness of specimens especially at low strain areas.
Fundamental Parameters of Cement-Admixed Clay—New Approach
The fundamental parameters such as after-curing void ratio (eot) and cement content (Aw) have been found sufficient to characterize the strength and compressibility of cement-admixed clay at high water contents. From analyses performed on the results of unconfined compression tests, the ratio eot/Aw has been proven to combine together the influences of clay water content, cement content, and curing time on the strength of cement-admixed clay. Moreover, the results of oedometer consolidation tests revealed that while Aw governs the position of the postyield compression line, the magnitude of eot determines the magnitude of the one-dimensional vertical yield stress σvy′ at particular Aw. The value of eot reflects, primarily, the clay water content and, secondarily, the cement content and the curing time. Normalizing the after-curing unit weight, after-curing water content, and after-curing specific gravity were incorporated in an empirical relationship of eot.
The Inca Occupation of the South Coast of Peru
like the others, however; it forks into several nearly parallel ravines of which the largest are Huayuri, Rio Grande-Palpa, Ingenio (called Collao in ancient times), Nasca proper (the ancient Caxamarca), Taruga, and Poroma. Due to peculiarities of the local topography, the irrigated areas in Ica and the ravines of Nasca are located inland, at the foot of the mountains, rather than at the mouths of the rivers as is more usual in Peruvian coastal valleys. No sharp natural or cultural boundary separates the valley of Chincha from the valleys of Cafiete (ancient Huarco and Runahuana), Asia, and Mala, the next valleys going up the coast to the northwest. At the other end of the area we are considering, however, there is a sharp break; beyond Yauca the Andean foothills reach out to the sea, natural conditions are quite different, and there are important differences in the archaeological picture as well. The historical sources which mention the south coast are not particularly helpful, except in so far as they provide us with a few dates. To begin with, no chronicler gives an explicit account of the political organization of the south coast at the time it came into contact with the Incas. It can, perhaps, be inferred from Cabello Balboa's statements about common policy toward the Inca invaders that there was some sort of political connection between the valleys of Mala, Cafiete, and Chincha, but the connection need have been no more than a temporary military alliance. Cabello makes no mention at all of Pisco. The valleys of Ica, Nasca, and 125