岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
5期
1032-1046
,共15页
边坡工程%黄土高边坡%开挖%土钉支护%桩钉复合支护%离心模型试验
邊坡工程%黃土高邊坡%開挖%土釘支護%樁釘複閤支護%離心模型試驗
변파공정%황토고변파%개알%토정지호%장정복합지호%리심모형시험
slope engineering%high loess slope%excavation%soil nailing%pile-soil nailing%centrifuge model test
为研究不同支护模式下黄土高边坡的开挖变形特征和支护结构性状，以观音堂隧道进口明洞段黄土高边坡为实例，采用土工离心机，开展黄土高边坡在无支护、全断面土钉支护、上部土钉下部预加固桩复合支护模式下的离心模型试验，试验结果表明：(1)桩-钉复合支护体系能够显著提高黄土高边坡的稳定性，坡体上部土钉的布设有效地调动了边坡更大范围内土体变形的调整，使得边坡土体的潜在滑移面向坡体内侧转移，将潜在滑移面的剪出口位置限制在预加固桩桩顶以下，而下部预加固桩的布设则有效地承担上部滑体的推力作用，保证坡体在开挖过程中的稳定性。(2)全断面土钉支护在一定程度上起到了加固边坡土体的作用，但由于土钉支护范围有限，当潜在滑移面深度超出土钉加固范围后，边坡土体发生更大范围内的失稳现象，加剧坡体的破坏。(3)对于黄土高边坡的加固，桩钉复合支护要优于全断面土钉支护。
為研究不同支護模式下黃土高邊坡的開挖變形特徵和支護結構性狀，以觀音堂隧道進口明洞段黃土高邊坡為實例，採用土工離心機，開展黃土高邊坡在無支護、全斷麵土釘支護、上部土釘下部預加固樁複閤支護模式下的離心模型試驗，試驗結果錶明：(1)樁-釘複閤支護體繫能夠顯著提高黃土高邊坡的穩定性，坡體上部土釘的佈設有效地調動瞭邊坡更大範圍內土體變形的調整，使得邊坡土體的潛在滑移麵嚮坡體內側轉移，將潛在滑移麵的剪齣口位置限製在預加固樁樁頂以下，而下部預加固樁的佈設則有效地承擔上部滑體的推力作用，保證坡體在開挖過程中的穩定性。(2)全斷麵土釘支護在一定程度上起到瞭加固邊坡土體的作用，但由于土釘支護範圍有限，噹潛在滑移麵深度超齣土釘加固範圍後，邊坡土體髮生更大範圍內的失穩現象，加劇坡體的破壞。(3)對于黃土高邊坡的加固，樁釘複閤支護要優于全斷麵土釘支護。
위연구불동지호모식하황토고변파적개알변형특정화지호결구성상，이관음당수도진구명동단황토고변파위실례，채용토공리심궤，개전황토고변파재무지호、전단면토정지호、상부토정하부예가고장복합지호모식하적리심모형시험，시험결과표명：(1)장-정복합지호체계능구현저제고황토고변파적은정성，파체상부토정적포설유효지조동료변파경대범위내토체변형적조정，사득변파토체적잠재활이면향파체내측전이，장잠재활이면적전출구위치한제재예가고장장정이하，이하부예가고장적포설칙유효지승담상부활체적추력작용，보증파체재개알과정중적은정성。(2)전단면토정지호재일정정도상기도료가고변파토체적작용，단유우토정지호범위유한，당잠재활이면심도초출토정가고범위후，변파토체발생경대범위내적실은현상，가극파체적파배。(3)대우황토고변파적가고，장정복합지호요우우전단면토정지호。
In order to study the behaviour of high loess slope excavated and supported with different reinforcement modes,a series of centrifuge tests were conducted to simulate the high loess slope at the entrance of Guanyintang tunnel,considering the excavations without the reinforcement,with the full-section soil nailing,and with the soil nailing at the upper part and the pre-installed stabilizing pile at the lower part(pile-soil nailing structure) respectively. The pile-soil nailing structure was found to improve greatly the stability of the high loess slope in the tests. The soil nails at the upper part mobilized effectively a much wider area of loess slope to deform. The inward migration of the potential sliding surface led the toe of potential sliding surface be lowered to the position below the top of the pre-installed stabilizing piles. As such,the pre- installed stabilizing piles at the lower part can effectively bear the thrust force exerted by soil slope and guarantee the stability of loess slope during excavation. The stability of the loess slope was improved to certain degrees in the case of the full-section soil-nailing. However,when potential sliding surface surpass the reinforcement region of the soil nailing,the soil slope collapses eventually. Therefore,the combined structure of pile-soil nailing is better than the full-section soil nailing for the reinforcement of high loess slope.
