Method for evaluating the in-plane shear strength of H-steal-reinforced wall-type ground improvement-Paper

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The study evaluates how embedded H-shaped steel affects the in-plane shear strength of cement-treated, wall-type ground improvement, and whether steel bars welded to the H-steel can preserve that strength. Such walls can help prevent liquefaction and may also serve as excavation retaining walls, but H-steel reinforcement may weaken in-plane resistance because the bond between steel and soil cement is limited.<br /><br />Researchers first conducted pull-out tests to measure the bond strength of reinforcing bars embedded in soil cement. They then performed structural shear tests on beam-shaped specimens, varying H-steel size and the number and diameter of bars welded to its web. Shear strength was assessed at the specimen’s elastic limit.<br /><br />Without additional bars, inserting H-steel reduced shear strength to about half that of a specimen without H-steel when the steel depth was 50% of the specimen width. The reduction was attributed to bond failure occurring before the soil cement’s full shear resistance could be mobilized. Small-diameter bars provided limited improvement, while two D13 bars raised strength to approximately 93% of the unreinforced specimen’s value. A smaller H-steel section, occupying 25% of the specimen width, also retained about 91% of the reference strength.<br /><br />The results indicate that strengthening the bond at the H-steel web can largely prevent loss of in-plane shear resistance. The authors note that bleeding and specimen-curing orientation may have affected measured bond performance, so field conditions require further consideration.

Keywords

H-shaped steel

in-plane shear strength

cement-treated soil

ground improvement

liquefaction prevention

excavation retaining wall

bond strength

pull-out test

shear test

steel bars reinforcement