针对湖北省宜昌市小溪塔至鸦鹊岭一级公路改建工程项目中广泛存在的膨胀土及当地可以充分利用的风化砂展开试验研究，分别针对原状膨胀土和掺入10 %~50 %的风化砂改良膨胀土进行击实试验及膨胀性指标室内试验。通过在原状膨胀土中掺入不同含量的风化砂进行试验，可以发现掺风化砂可以改变膨胀土的含水特性和密实特性；掺不同含量的风化砂对膨胀土的膨胀性指标影响较大，可以显著抑制膨胀土的膨胀性，达到路基填料的标准。

Aiming at widespread presence of expansive soil which canbe obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand which can be made full use of locally, many experiments were made. Compaction experiments and expansibility index indoor experiments of undisturbed expansive soil and expansive soil mixed with sand range from 10 % to 50 % were made. Through the test of undisturbed expansive soil mixed with different content of weathered sand, it was found that undisturbed expansive soil mixed with weathered sand can change the expansive soil water characteristics and compaction characteristics. Undisturbed expansive soil mixed with different content of weathered sand can influence the expansibility of the expansive soil index and significantly inhibit the expansibility of the expansive soil and reach the standard of roadbed filler.