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The article discusses the article "The State of the Practice in Foundation Engineering on Expansive and Collapsible Soils" by William N. Houston and John D. Nelson. The authors of the article say that a careful designer should perform sufficient analyses or investigation to set up within reasonable certainty the design active zone for the life of the structure.

The principal objective of this study is the development and calibration of a macroelement model for soil-pile interaction under simultaneously applied lateral and vertical loads. Herein, we focus on cast-in-drilled-hole single piles that are partially or fully embedded in soil, which are frequently used as support structures in highway construction. The model is calibrated and verified using primarily three-dimensional finite-element simulations and, whenever possible, with experimental data obtained from open literature. These data indicate that lateral loads significantly affect the vertical response of single piles, whereas the converse coupling is negligible. The proposed macroelement model is capable of mimicking this phenomenon. As such, it is a computationally efficient alternative to finite-element analyses, and is feasible to be utilized in practical applications. [ABSTRACT FROM AUTHOR]

Traditional bearing capacity theories for the ultimate capacity of shallow foundations assume that the thickness of the bearing stratum is infinite. The presence of a hard layer within a certain depth below the foundation can significantly influence the unit load supported by the soil. Therefore the original bearing capacity equations should be modified to account for this condition in determining the ultimate bearing capacity. In order to evaluate this phenomenon further, model square and circular footing tests were performed on a bed of well-graded sand. Test beds were prepared at three different relative densities corresponding to loose, medium, and dense conditions: Dr=24, 57, and 87%, using five different sand layer thicknesses, H; H/B values of 0.5, 1, 2, 3, and 4, where B is the footing width. Results of the model scale footing tests show that the bearing capacity factor, Nγ, should be modified up to H/B=3, instead of H/B=1, as previously suggested. The footing shape factor, sγ, should account for both shape and finite layering. This technical note gives a description of the test methods and material used and presents the test results in comparison to previous results. [ABSTRACT FROM AUTHOR]

The article presents response on the comment regarding the study on the minimum foundation mass for vibration control. It agrees with the discusser's findings that the dynamics of embedded foundations on layered soil cannot be studied through the simple design method proposed by the authors. It also recognizes the clearness of the author's method, which is based on the analog models of force vibration of a rigid disk.

The article discusses the study involving high-modulus columns for liquefaction mitigation. The authors resort to the Chinese criteria to support their argument of liquefaction and emphasize the similarity of ML/CL soils of the site to those encountered in Adapazari, Turkey which were presumed to have liquefied during the Kocaeli earthquake on the basis of observed displacements of building foundations. The authors compared performance of the supermarket building area which was strengthened through construction of jet-grout columns.

Comments on the article "Performance of Tension and Compression Anchors in Weathered Soil," by Nak-Kyung Kim in the December 2003 issue. Investigation on ground-anchor behavior; Need for researchers to be wary of defining "ultimate load" prior to full anchor failure being exhibited; Observation that the paper did not demonstrate anchor failure loads.