Engineering properties of Houston subsoils
Johnson, Delbert Benjamin
Sims, James R.
Master of Science
Presented in this thesis is a summary of Houston subsoils data as obtained from geological considerations and a substantial portion of the available records of test borings and soils tests. From this summary, the following observations may be made. The subsoils of Houston consist of clays, fine sands and silts which were deposited by water during late Pleistocene time and Recent time. Recent deposits are found only along streams; all other soils are Pleistocene. Clay deposits make up the predominant soil type. Clays may contain large percentages of silt and sand which measurably alter their physical properties. Depending on the quantity of sand which a clay possesses, it may be classified as either sandy or plastic. Sandy clays usually possess high internal friction as well as cohesive strength. Stiff plastic clays possess variable internal friction and are characteristically jointed or fissured, a fact which often alters the results of compressive tests. Sand deposits appear as lenses which are often interbedded in more extensive strata of clay. These deposits consist chiefly of fine to very fine sands and often contain appreciable amounts of silt. Relative densities of the sands vary from loose to dense.