工程地质学报
工程地質學報
공정지질학보
2015年
3期
498-504
,共7页
王红雨%唐少容%邢毓航%张学科
王紅雨%唐少容%邢毓航%張學科
왕홍우%당소용%형육항%장학과
宽级配砾质土%冻融循环%渗透试验%复合防渗系统
寬級配礫質土%凍融循環%滲透試驗%複閤防滲繫統
관급배력질토%동융순배%삼투시험%복합방삼계통
Compacted gravel soils%Freeze-thaw cycling%Penetration experiment%Composite liners system
针对西北地区特殊的气候条件和砾质土料源丰富的实际情况，提出采用宽级配砾质土代替黏土作为土工合成材料膨润土垫（GCls）的保护层共同构成垃圾填埋场复合防渗系统的构想。文中选取宁夏银川地区冲－洪积作用形成的天然砾质土料，经人工掺和制配成满足规范对 GCls 防渗垫保护层渗透系数要求的宽级配砾质土样，在实验室对该土样进行了冻融循环作用下的渗透性能试验研究。结果显示，随着冻融次数的逐渐增加，土样的冻胀率逐渐变大，渗透系数也相应增大，经过12次冻融循环后，渗透系数约增大1～2个数量级；冻融循环初期，冻融作用对土样的影响最为剧烈，随着冻融循环次数的增加以及时间的延续，土样性状逐渐趋于稳定。由于宽级配砾质土对冻融循环作用的敏感性小于粉质黏性土，故采用宽级配砾质土作为 Cls／GM的保护层共同组成填埋场复合防渗系统是值得期待的。
針對西北地區特殊的氣候條件和礫質土料源豐富的實際情況，提齣採用寬級配礫質土代替黏土作為土工閤成材料膨潤土墊（GCls）的保護層共同構成垃圾填埋場複閤防滲繫統的構想。文中選取寧夏銀川地區遲－洪積作用形成的天然礫質土料，經人工摻和製配成滿足規範對 GCls 防滲墊保護層滲透繫數要求的寬級配礫質土樣，在實驗室對該土樣進行瞭凍融循環作用下的滲透性能試驗研究。結果顯示，隨著凍融次數的逐漸增加，土樣的凍脹率逐漸變大，滲透繫數也相應增大，經過12次凍融循環後，滲透繫數約增大1～2箇數量級；凍融循環初期，凍融作用對土樣的影響最為劇烈，隨著凍融循環次數的增加以及時間的延續，土樣性狀逐漸趨于穩定。由于寬級配礫質土對凍融循環作用的敏感性小于粉質黏性土，故採用寬級配礫質土作為 Cls／GM的保護層共同組成填埋場複閤防滲繫統是值得期待的。
침대서북지구특수적기후조건화력질토료원봉부적실제정황，제출채용관급배력질토대체점토작위토공합성재료팽윤토점（GCls）적보호층공동구성랄급전매장복합방삼계통적구상。문중선취저하은천지구충－홍적작용형성적천연력질토료，경인공참화제배성만족규범대 GCls 방삼점보호층삼투계수요구적관급배력질토양，재실험실대해토양진행료동융순배작용하적삼투성능시험연구。결과현시，수착동융차수적축점증가，토양적동창솔축점변대，삼투계수야상응증대，경과12차동융순배후，삼투계수약증대1～2개수량급；동융순배초기，동융작용대토양적영향최위극렬，수착동융순배차수적증가이급시간적연속，토양성상축점추우은정。유우관급배력질토대동융순배작용적민감성소우분질점성토，고채용관급배력질토작위 Cls／GM적보호층공동조성전매장복합방삼계통시치득기대적。
The design conception of composite liners is consisted of a geomembrane(GM),geosynthetic clay liners (GCls) and compacted gravel soils in landfills.This conception is presented on the basis of the climate characteristics,gravel soils material rich in nature,and GCls that have been exported all over the world for various applications.The artificially graded gravel soils are taken from natural sediment zone for flood alluvial at Yinchuan suburb in Ningxia.The gravel soil is figured out to meet the requirement of permeability coefficient through the compaction and penetration experiment.The frost-heaving ratio and hydraulic conductivity of gravel soil samples are tested under freeze-thaw cycling in this paper.The test results indicate that the frost-heaving ratio increases as the number of freeze-thaw increases.As the number of freeze-thaw increases,the permeability coefficient also increases. The permeability coefficient is increased by one to two orders of magnitude after 12 cycles of freezing-thawing.At the beginning of freeze-thaw cycle,it has an influence on the soil samples.The influence tends to be relatively stable state as the number of freeze-thaw cycles increases.The sensitivity of gravel soils under freeze-thaw cycling is less than that of the silt clay.It is acceptable to undertake the landfill composite liners which will be comprised of GCls/GMand compacted gravel soils together.
