岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
7期
1854-1860
,共7页
刘泉声%柳志平%程勇%贾瑞华
劉泉聲%柳誌平%程勇%賈瑞華
류천성%류지평%정용%가서화
水泥土%侵蚀性%力学试验%化学动力学%等效分析
水泥土%侵蝕性%力學試驗%化學動力學%等效分析
수니토%침식성%역학시험%화학동역학%등효분석
cemented soil%erosion%mechanical test%chemical kinetics%equivalent analysis
拱北隧道是港珠澳大桥连接线的重要组成部分，隧道基底采用水泥土加固体处理。在加固体所处的环境中，由于地下承压水与海水相连，海水中所含的侵蚀性离子易对加固体产生一定的影响。通过室内试验和理论推导，研究侵蚀环境下水泥土的力学性能和耐久性。自制水泥土试块并模拟侵蚀环境，水泥土试块在侵蚀环境中浸泡时间分别为90、180、270 d，对浸泡后的水泥土试块进行无侧限抗压试验。试验结果表明：在侵蚀环境的影响下，水泥土试块强度的最大值出现在90～270 d之间。浸泡时间超过90 d，氯化镁和氯化钠的混合溶液（MCN）使水泥土试块的抗压强度表现出明显的衰减响应。在低浓度（1.5 g/L和4.5 g/L）条件下，MSN中的硫酸镁与水泥土中的3CaO·2SiO2·3H2O充分反应，使水泥土的抗压强度达到最高值，同比情况下对水泥土的抗压强度损伤最小。在相同的浓度下，氯化镁对水泥土试块的抗压强度影响比硫酸镁大。从化学动力学基本原理出发，基于硫酸镁与水泥水化产物的化学反应过程，推导得出侵蚀性溶液浓度与侵蚀时间之间的关系式(C1/C2)β=t2/t1，即当水泥土被侵蚀后达到同等抗压强度时，侵蚀性物质浓度的反应级数次方与侵蚀时间成反比。根据公式，可以通过较高浓度的侵蚀性溶液对水泥土试样浸泡较短时间条件下的强度试验结果，预测分析较低浓度的侵蚀性溶液对水泥土试样浸泡较长时间条件下的水泥土强度。最后结合试验数据对理论结果进行了验证。
拱北隧道是港珠澳大橋連接線的重要組成部分，隧道基底採用水泥土加固體處理。在加固體所處的環境中，由于地下承壓水與海水相連，海水中所含的侵蝕性離子易對加固體產生一定的影響。通過室內試驗和理論推導，研究侵蝕環境下水泥土的力學性能和耐久性。自製水泥土試塊併模擬侵蝕環境，水泥土試塊在侵蝕環境中浸泡時間分彆為90、180、270 d，對浸泡後的水泥土試塊進行無側限抗壓試驗。試驗結果錶明：在侵蝕環境的影響下，水泥土試塊彊度的最大值齣現在90～270 d之間。浸泡時間超過90 d，氯化鎂和氯化鈉的混閤溶液（MCN）使水泥土試塊的抗壓彊度錶現齣明顯的衰減響應。在低濃度（1.5 g/L和4.5 g/L）條件下，MSN中的硫痠鎂與水泥土中的3CaO·2SiO2·3H2O充分反應，使水泥土的抗壓彊度達到最高值，同比情況下對水泥土的抗壓彊度損傷最小。在相同的濃度下，氯化鎂對水泥土試塊的抗壓彊度影響比硫痠鎂大。從化學動力學基本原理齣髮，基于硫痠鎂與水泥水化產物的化學反應過程，推導得齣侵蝕性溶液濃度與侵蝕時間之間的關繫式(C1/C2)β=t2/t1，即噹水泥土被侵蝕後達到同等抗壓彊度時，侵蝕性物質濃度的反應級數次方與侵蝕時間成反比。根據公式，可以通過較高濃度的侵蝕性溶液對水泥土試樣浸泡較短時間條件下的彊度試驗結果，預測分析較低濃度的侵蝕性溶液對水泥土試樣浸泡較長時間條件下的水泥土彊度。最後結閤試驗數據對理論結果進行瞭驗證。
공북수도시항주오대교련접선적중요조성부분，수도기저채용수니토가고체처리。재가고체소처적배경중，유우지하승압수여해수상련，해수중소함적침식성리자역대가고체산생일정적영향。통과실내시험화이론추도，연구침식배경하수니토적역학성능화내구성。자제수니토시괴병모의침식배경，수니토시괴재침식배경중침포시간분별위90、180、270 d，대침포후적수니토시괴진행무측한항압시험。시험결과표명：재침식배경적영향하，수니토시괴강도적최대치출현재90～270 d지간。침포시간초과90 d，록화미화록화납적혼합용액（MCN）사수니토시괴적항압강도표현출명현적쇠감향응。재저농도（1.5 g/L화4.5 g/L）조건하，MSN중적류산미여수니토중적3CaO·2SiO2·3H2O충분반응，사수니토적항압강도체도최고치，동비정황하대수니토적항압강도손상최소。재상동적농도하，록화미대수니토시괴적항압강도영향비류산미대。종화학동역학기본원리출발，기우류산미여수니수화산물적화학반응과정，추도득출침식성용액농도여침식시간지간적관계식(C1/C2)β=t2/t1，즉당수니토피침식후체도동등항압강도시，침식성물질농도적반응급수차방여침식시간성반비。근거공식，가이통과교고농도적침식성용액대수니토시양침포교단시간조건하적강도시험결과，예측분석교저농도적침식성용액대수니토시양침포교장시간조건하적수니토강도。최후결합시험수거대이론결과진행료험증。
Gongbei tunnel is an important part of Hong Kong-Zhuhai-Macao Bridge cable; its foundation pit bottom is dealt with cemented soil. The aggressive ions of the sea will easily have an effect on the cemented soil as the underground pressure water is connected to the brine. Through the laboratory experiment and theoretical deduction, the mechanical properties and durability of cemented soil in the corrosion environment are studied as follows. Laboratory cemented soil and corrosion environment are made to test the unconfined compression strength of the samples soaked at 90 d, 180 d and 270 d respectively. Result of this laboratory experiment indicates that: under the influence of erosion environment, the maximum value of uniaxial compressive strength of cement soil will be reached between 90 d and 270 d. After the soak period exceeds 90 d, the solution that contains MCN shows up an entirely negative effect on the compressive strength of cemented soil. Under low concentration (1.5 g/L and 4.5 g/L), the chemical reaction between MSN and cemented soil achieves an optimum value; in comparative conditions the compression strength damage of cement soil is minimal. The effect of magnesium chloride on compressive strength of the cemented soil samples is much larger than that of magnesium sulfate. Based on the principle of chemical kinetics and the chemical equation between magnesium sulfate and the cement hydration products, combined with the assumptions, the relationship between ion concentration and corrosion time is deduced as (C1/C2)β=t2/t1; that is, when the soil samples are eroded to equivalent compression strength, the reaction order of concentration is inversely proportional to corrosion time. According to the formula, the strength of cemented soil soaking in low concentration solution for a long time is predicted by the strength of cemented soil soaking in high concentration solution for a short time. At last, the theoretical results are verified by experimental data.
