岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
2期
504-510
,共7页
隧道冻结%地表融沉%解冻过程%预测模型%随机介质理论
隧道凍結%地錶融沉%解凍過程%預測模型%隨機介質理論
수도동결%지표융침%해동과정%예측모형%수궤개질이론
tunnel freezing%surface thawing settlement%thawing process%prediction model%stochastic medium theory
隧道冻结工程中所形成的人工冻结壁为临时支护结构，隧道衬砌结构施工后，冻结壁要进入解冻期，由于冻结壁解冻过程中的地层融沉现象对隧道周边环境影响较大，因此，应建立合理的方法对地表融沉量进行预测，以便于实际施工中采取相应的融沉控制措施。为此，考虑冻结壁的自然解冻过程，基于随机介质理论，建立了隧道水平冻结施工期地表融沉的历时预测模型。并提出冻结壁自然解冻条件下瞬态温度场由平板解冻理论近似求解，基于平板解冻理论和一维情况下已融土层的稳定融沉量计算公式，确定了预测模型中解冻锋面半径和融缩区域内半径这2个关键参数的取值方法。将所建立的预测模型应用于隧道全断面水平冻结工程中，得到了地表融沉随解冻时间的变化规律。研究结果表明，地表融沉在解冻初期增长速度较快，而在解冻后期增长速度减缓，地表历时融沉量与崔托维奇通过试验得出的天然冻土历时融沉量变化规律相一致。
隧道凍結工程中所形成的人工凍結壁為臨時支護結構，隧道襯砌結構施工後，凍結壁要進入解凍期，由于凍結壁解凍過程中的地層融沉現象對隧道週邊環境影響較大，因此，應建立閤理的方法對地錶融沉量進行預測，以便于實際施工中採取相應的融沉控製措施。為此，攷慮凍結壁的自然解凍過程，基于隨機介質理論，建立瞭隧道水平凍結施工期地錶融沉的歷時預測模型。併提齣凍結壁自然解凍條件下瞬態溫度場由平闆解凍理論近似求解，基于平闆解凍理論和一維情況下已融土層的穩定融沉量計算公式，確定瞭預測模型中解凍鋒麵半徑和融縮區域內半徑這2箇關鍵參數的取值方法。將所建立的預測模型應用于隧道全斷麵水平凍結工程中，得到瞭地錶融沉隨解凍時間的變化規律。研究結果錶明，地錶融沉在解凍初期增長速度較快，而在解凍後期增長速度減緩，地錶歷時融沉量與崔託維奇通過試驗得齣的天然凍土歷時融沉量變化規律相一緻。
수도동결공정중소형성적인공동결벽위림시지호결구，수도츤체결구시공후，동결벽요진입해동기，유우동결벽해동과정중적지층융침현상대수도주변배경영향교대，인차，응건립합리적방법대지표융침량진행예측，이편우실제시공중채취상응적융침공제조시。위차，고필동결벽적자연해동과정，기우수궤개질이론，건립료수도수평동결시공기지표융침적력시예측모형。병제출동결벽자연해동조건하순태온도장유평판해동이론근사구해，기우평판해동이론화일유정황하이융토층적은정융침량계산공식，학정료예측모형중해동봉면반경화융축구역내반경저2개관건삼수적취치방법。장소건립적예측모형응용우수도전단면수평동결공정중，득도료지표융침수해동시간적변화규률。연구결과표명，지표융침재해동초기증장속도교쾌，이재해동후기증장속도감완，지표력시융침량여최탁유기통과시험득출적천연동토력시융침량변화규률상일치。
Artificially frozen wall is a temporary support structure in tunnel freezing engineering;and frozen wall will gradually thaw after construction of the tunnel lining. In the process of frozen wall thawing, thawing settlement of ground can produce serious influence on the surrounding environment. So a reasonable method must be established for predicting surface thawing settlement. On this basis, suitable thawing settlement prevention measures can be determined in the actual construction. For this reason, considering the thawing process of frozen wall, using stochastic medium theory, a duration prediction model of surface thawing settlement in the period of tunnel construction with horizontal freezing method is presented. Temperature field under natural thawing conditions can be approximately analyzed by flat-panel thawing theory;based on flat-panel thawing theory and thawing settlement content calculation formula in one-dimensional case, value methods of thaw front radius and thaw compression region inner radius are determined in the duration prediction model. The prediction method is applied to circular tunnel full section horizontal freezing engineering, surface thawing settlement variations with thawing time are presented. The results show that surface thawing settlement grows faster in the early stages of thawing, and grows slower in the later stages of thawing. Surface thawing settlement variations with thawing time is presented, which is consistent with thawing settlement characteristics of natural permafrost researched through test method byЦЫТОВНИЧ.
