初始干密度对天然砂砾改良红粘土回弹模量的影响及预估模型

Impact and prediction model of initial dry density on resilient modulus of gravel soil red clay

以掺天然砂砾改良的红粘土为研究对象,采用室内承载板法测定回弹模量,通过不同初始干密度下的回弹模量试验,深入研究了天然砂砾改良红粘土的回弹模量随初始干密度的变化规律,建立了不同初始干密度下回弹模量的预估模型。试验结果表明:在同一天然砂砾掺量下,随着初始干密度的提高,红粘土的回弹模量逐渐增大。当初始干密度由低向最大干密度增大时,回弹模量增长速度较快,当初始干密度超过最大干密度继续增大时,回弹模量增长速度变缓;在同一初始干密度下,当天然砂砾掺量从0增至30%时,回弹模量的增长幅度较小,当天然砂砾掺量超过30%而继续增长时,回弹模量增长幅度较大;初始干密度由1.6g·cm-3增长至2.0g·cm-3时,回弹模量增长值随天然砂砾掺量的增加而逐渐增大。分别建立了回弹模量随初始干密度及天然砂砾掺量变化的预估模型,通过补充试验,验证了预估模型的准确性。

The gravel soil red clay was used to in resilient modulus test under the condition of different initial dry density and the the resilient modulus variation was studied. The prediction model of resilient modulus was established. The test results show that： （1） With the same gravel soil content, when the initial dry density increases,the resilient modulus of red clay increases. When the initial dry density increases from low to maximum dry density, resilient modulus grow faster and when the initial dry density increased after exceeding the maximum dry density, esilient modulus grow slower ;（2） With the same initial dry density,when the gravel content increases from 0 to 30~, the growth rate of resilient modulus is lower and when the gravel content continues to grow, the growth rate of resilient modulus is greater; （3） When the initial dry density increases from 1. 6 g· cm 3 to 2. 0 g· cm 3, resilient modulus growth values gradually increases with increasing content of gravel soil; （4） The prediction model of resilient modulus was established the and the accuracy of the prediction model was ,verified.