พฤติกรรมด้านกำลังและการกัดเซาะของทรายปนดินเหนียวต่อการเปลี่ยนแปลงระดับขั้นการอิ่มตัวด้วยน้ำ: กรณีศึกษาลาดดินที่ปกคลุมด้วยวัสดุใยธรรมชาติ

Abstract

This paper reports studies on strength, and erodibility of clayey sand from the direct shear test with suction measurement, Pinhole test as well as field measurement. The undisturbed samples were taken from two test plots, which are covered with two different bio-stabilization systems, namely, plot 1) Erosion control log – Erosion control blanket (natural geotextile)- with Ruzi grass; and plot 2) Erosion control log with rows of Vetiver grass. At suction range of 0-30 kPa, the soil from plot 1 exhibits higher shear strength than plot 2, due to the greater fine contents.  A higher suction has been observed in the uncovered plot 2 which appears to be more prone to erosion. This is due to its excessively low degree of saturation. This trend is also observed in the pinhole tests. It is concluded that the soil blankets help prevent the migration of fine particles from the soil, maintain its suction cohesion and appropriate moisture condition, thus increasing its erosion resistance.