[摘要]環保防滲膜減少基礎凍脹量。可凍性土壤、水份、負溫是產生凍脹的三個必要條件，改變產生凍脹的條件是解決凍脹問題最有效的辦法。用砂礫層墊層置換渠床原狀土，改變基礎土質條件，
環(huan)保防滲(shen)(shen)(shen)膜(mo)減少基礎凍(dong)(dong)(dong)脹(zhang)量。可凍(dong)(dong)(dong)性土(tu)壤(rang)、水份、負(fu)溫(wen)是(shi)產生凍(dong)(dong)(dong)脹(zhang)的三個(ge)必要(yao)條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)，改變產生凍(dong)(dong)(dong)脹(zhang)的條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)是(shi)解決凍(dong)(dong)(dong)脹(zhang)問題最有(you)效(xiao)的辦法。用砂礫層墊層置(zhi)換(huan)渠床原狀土(tu)，改變基礎土(tu)質條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)，減少或(huo)消(xiao)除凍(dong)(dong)(dong)脹(zhang)；改變水份條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)，在(zai)(zai)鋼性襯(chen)(chen)砌(qi)面(mian)下(xia)鋪設(she)(she)高效(xiao)防滲(shen)(shen)(shen)材料，如(ru)(ru)塑料防滲(shen)(shen)(shen)膜(mo)、土(tu)工膜(mo)，同時(shi)(shi)在(zai)(zai)渠底加設(she)(she)排(pai)水設(she)(she)施，如(ru)(ru)在(zai)(zai)挖(wa)方渠段設(she)(she)排(pai)水溝(gou)渠，在(zai)(zai)有(you)滲(shen)(shen)(shen)水外排(pai)條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)的填(tian)方渠段，把(ba)滲(shen)(shen)(shen)入換(huan)填(tian)砂礫石墊層中的水份排(pai)出有(you)效(xiao)凍(dong)(dong)(dong)脹(zhang)層，消(xiao)除凍(dong)(dong)(dong)脹(zhang)，同時(shi)(shi)做好保溫(wen)襯(chen)(chen)砌(qi)，在(zai)(zai)剛性襯(chen)(chen)砌(qi)的下(xia)面(mian)鋪設(she)(she)一(yi)層保溫(wen)層（如(ru)(ru)聚苯乙烯(xi)泡沫保溫(wen)板），形(xing)成保溫(wen)襯(chen)(chen)砌(qi)結構，改變基土(tu)溫(wen)度條(tiao)(tiao)(tiao)件(jian)(jian)(jian)(jian)，減少或(huo)消(xiao)除凍(dong)(dong)(dong)脹(zhang)