NEHRP Clearinghouse
- Title
- Seismic Characteristics of Sediments in the New Madrid Seismic Zone.
- File
- PB93121937.pdf
- Author(s)
- Chang, T. S.; Teh, L. K.; Zhang, Y.
- Source
- National Science Foundation, Washington, DC., February 1992, 157 p.
- Abstract
- The most critical and essential information required for seismic studies is the determination of dynamic properties and stratification of the underlying soils. According to state-of-the-art geotechnical techniques, strain-dependent nonlinear modulus and damping, which are the important dynamic properties of soils for strong ground motion and liquefaction studies, can be determined only in the laboratory. A total of 58 samples of soils were collected from the local government agencies and engineering consulting companies. Thirty-five samples of soils in the northern Mississippi embayment region were selected for the dynamic testing program through use of the resonant column techniques for measuring low-strain shear modulus, high-strain modulus degradation characteristics, and damping ratio. In general, the test results agree with the results of previous studies of soil dynamics: namely, the shear modulus increases with increasing static shear strength (smaller void ratio of sand and higher shear strength of clay) and increasing confining pressure, but decreases with increasing shear strain. For all samples tested, damping ratio decreases as modulus increases.
- Keywords
- Mississippi; Strains; New Madrid Seismic Zone; Test facilities; Tennessee; Arkansas; Damping; Shear properties; Dynamic response; Earthquake engineering; Soil pressure; Soil properties; Sands; Seismic effects; Soil mechanics; Sediments; Soil tests