本文關(guān)鍵詞： 邊坡工程 小直徑鋼管樁 排樁 抗滑機理 計算方法 承載力影響因素 失效準則　出處：《西南交通大學(xué)》2013年博士論文　論文類型：學(xué)位論文

【摘要】：小直徑鋼管排樁作為新型邊坡支擋結(jié)構(gòu),具有施工快捷安全、承載力強、加固見效快、經(jīng)濟效益好等優(yōu)點。由于缺乏抗滑機理、計算方法等方面的系統(tǒng)研究,嚴重制約了鋼管排樁作為永久支擋結(jié)構(gòu)的推廣應(yīng)用。本文利用工程樁監(jiān)測試驗、原型結(jié)構(gòu)堆載試驗、離心機模型試驗、理論分析及數(shù)值模擬等手段,系統(tǒng)研究了鋼管排樁基于樁土相互作用的受力變形規(guī)律、抗滑機理、承載力影響因素等內(nèi)容,提出了力學(xué)計算模型和實用設(shè)計計算方法,為鋼管排樁從應(yīng)急搶險功能向永久性支擋工程推進提供了基礎(chǔ)資料和理論基礎(chǔ)。 1.鋼管排樁支擋結(jié)構(gòu)抗滑機理主要表現(xiàn)為：1)在鋼管排樁空間框架約束下,樁間土體具有強化效應(yīng),框架內(nèi)土體承載能力得到提高；2)排架土體與鋼管樁協(xié)調(diào)變形,通過樁土相互作用傳遞荷載、形成樁土復(fù)合承載結(jié)構(gòu),大幅提高鋼管排樁承載能力；3)樁間土體具有明顯的土拱效應(yīng),土拱作用具有維持樁間土穩(wěn)定、傳遞樁間荷載的作用,并通過約束排架土體,強化了支擋結(jié)構(gòu)承載能力；4)壓力注漿增大鋼管樁剛度、改善土體性質(zhì),增強了樁土復(fù)合結(jié)構(gòu)承載能力。 2.通過原型結(jié)構(gòu)堆載極限破壞試驗,得出了鋼管排樁在試驗條件下的水平極限承載能力：厚度為8-12m,以硬黏土、塊石土為主的滑坡,采用直徑133mm直縫鋼管、間排距1.5-1.7m、鋼筋砼系梁的鋼管排樁進行支擋,三排樁承載力為531kN/m,兩排樁承載力為390kN/m；實際應(yīng)用中為確保支擋工程安全,應(yīng)采用設(shè)計安全系數(shù)1.5-2,即三排樁承受水平推力一般不大于350kN/m,兩排樁承受水平推力一般不大于260kN/m。 3.通過現(xiàn)場堆載試驗、離心機模型試驗及數(shù)值分析,總結(jié)出各相關(guān)因子對鋼管排樁承載能力影響規(guī)律：增加鋼管樁排數(shù)可增大支擋結(jié)構(gòu)承載能力；樁間距與樁徑之比L/d15時,樁間土通過土拱作用維持穩(wěn)定,同時為避免出現(xiàn)群樁效應(yīng),L/d宜≥8；排距與直徑之比b/d為6-12時,樁土復(fù)合作用發(fā)揮最充分,支擋結(jié)構(gòu)支護能力最強,為避免出現(xiàn)群樁效應(yīng),b/d宜≥8；強剛度系梁具有協(xié)調(diào)鋼管樁內(nèi)力、約束土體加強樁土復(fù)合承載的作用；樁間土體物理力學(xué)性質(zhì)越好,樁土復(fù)合作用發(fā)揮越充分,支擋結(jié)構(gòu)抗滑能力越強。 4.小直徑鋼管排樁在水平荷載作用下,排架內(nèi)土體與鋼管樁協(xié)調(diào)變形；排架土體通過樁土相互作用將水平荷載q傳遞至其他排樁,各排樁承受荷載qi分布規(guī)律與q致,量值為qi=ξq,對于三排樁,ξ1=0.95,ξ2=0.90,兩排樁ξ1=0.94,ξ2=0；小直徑鋼管排樁骨架結(jié)構(gòu)可假定為承受水平荷載q、樁間土傳遞荷載qi、樁前土體抗力p(少,z)、錨固段抗力p'(y,z)的平面剛架模型,其中樁前土體抗力p(y,z)采用p-y曲線描述,錨固段抗力p'(y,z)采用線性彈簧模擬。 5.對考慮樁土復(fù)合作用的平面剛架計算模型,分別采用彈性地基梁法、p-y曲線法進行內(nèi)力變形計算,通過與實測資料對比分析,p-y曲線法計算結(jié)果與實測值吻合較好,同時該法充分反應(yīng)了土體彈塑性特征,計算便捷,可作為工程應(yīng)用推廣。 6.根據(jù)鋼管排樁抗滑機理、計算方法研究成果,提出了支擋結(jié)構(gòu)按承載力和位移控制的失效準則、實用設(shè)計計算方法及步驟、適用條件。 7.結(jié)合工程實踐研究了鋼管排樁作為永久結(jié)構(gòu)的接管技術(shù)和長效防腐方法：鋼管接管技術(shù)可采用三截面內(nèi)襯管搭接式焊接法(己獲國家實用新型專利,專利號：ZL201220616390.1)；防腐方法可采用鋼管外壁熱噴涂鋅,結(jié)合管外砂漿包裹隔離防腐。通過工程實踐應(yīng)用,上述鋼管連接和防腐方法可保障結(jié)構(gòu)可靠性和耐久性。
[Abstract]:As a new type of small diameter steel tubular pile slope retaining structure, the construction is safe and fast, strong bearing capacity, strengthening the advantages of quick effect, good economic benefit and so on. Due to the lack of systematic research on the anti sliding mechanism, calculation methods, seriously restrict the pipe pile as a permanent retaining structure. The popularization and application of the project piling monitoring test prototype structure loading test, centrifuge model test, theoretical analysis and numerical simulation, the system of steel pipe piles based on the soil pile interaction force and deformation, the anti sliding mechanism, bearing capacity factors etc., put forward the mechanical calculation model and practical design method for steel pipe. Pile from emergency rescue function to permanent retaining engineering in advance to provide basic data and theoretical basis.
1. pipe pile retaining structure anti slide mechanism mainly as follows: 1) in pipe pile space frame under the constraint of soil between piles with reinforcement effect, within the framework of soil bearing capacity is improved; 2) bent steel pipe pile soil and coordinated deformation and load transfer through the pile soil interaction, the formation of the pile composite bearing the structure, greatly improve the bearing capacity of steel pipe pile; 3) soil has obvious soil arching effect, soil arching effect can maintain the stability of soil between piles, pile load transfer function, and the constraint frame soil retaining structure, strengthening capacity; 4) increase the stiffness of steel pipe pile pressure grouting and improve the properties of soil, enhance bearing pile composite structure.
2. the prototype structure load ultimate failure test, the ultimate horizontal pipe pile under the condition of test bearing capacity: thickness of 8-12m, with hard clay, stone soil landslide, with the diameter of 133mm pipe, spacing 1.5-1.7m, steel reinforced concrete beam pile for retaining three. Pile bearing capacity is 531kN/m, two rows of pile bearing capacity is 390kN/m; in order to ensure the safety of retaining engineering in practical application, should adopt the design safety factor of 1.5-2, namely the three row pile under horizontal thrust is generally not more than 350kN/m, two rows of pile under horizontal thrust is generally not more than 260kN/m.
3. through field loading test, model test and numerical analysis of centrifuge, summed up the related factors of pipe pile bearing capacity influence: increasing the row number of steel pipe pile retaining structure can increase the bearing capacity of pile spacing and pile diameter; the ratio of L/d15, the soil arching effect of soil between piles is stable, appear at the same time group in order to avoid the effect of pile, L/d should be equal to or greater than 8; row spacing and diameter ratio of b/d is 6-12, the pile composite function fully, retaining structure supporting ability is the strongest, appear to avoid the pile group effect, b/d should be greater than or equal to 8; the strong stiffness beam has the coordination of steel pipe pile internal force, soil pile strengthening constraints the effect of pile soil composite bearing; physical and mechanical properties of soil as the pile composite role more fully, retaining structure of anti slide ability is stronger.
4. small diameter steel pipe piles under horizontal loads, the soil inside the frame and steel pipe pile deformation; bent soil by soil pile interaction to horizontal load Q transmission to other rows of piles, each pile load distribution of Qi and Q, qi=. Q value, for the three row pile. 0.95. 1=, 2=0.90., two rows of piles. 1=0.94. 2=0; small diameter steel pipe piles can be assumed as a skeleton structure under the horizontal load Q, soil load transfer Qi between piles, pile soil resistance of P (small z), anchorage resistance of p'(y, z) plane frame model. The anterior surface of the pile resistance of P (y, z) by p-y curve description, anchoring force p' (y, z) by using the linear spring element.
5. to consider the interaction of soil pile composite plane frame model, using elastic foundation beam method, p-y curve method to calculate the internal forces and deformation, through analysis and comparison with the field data. The calculation results agree well with the measured values of p-y curve method, while the method fully reflects the elastoplastic characteristics, calculation is convenient, can be used as engineering application.
6., according to the research results of the slide resistance mechanism and calculation method of steel pipe piles, the failure criterion of supporting structure according to the bearing capacity and displacement control is put forward, and the practical design calculation methods and steps, and applicable conditions are put forward.
7. combined with the engineering practice of steel pipe pile as a takeover and anticorrosive method of permanent structure: steel pipe technology can adopt three section liner lap welding method (has won the national utility model patent, patent number: ZL201220616390.1); anticorrosion methods can be made of steel tube thermal spraying zinc binding mortar wrapped isolation tube anticorrosion. Through the application of engineering practice, the steel pipe and anticorrosion method can ensure the reliability and durability of the structure.

【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TU473.1

【參考文獻】

相關(guān)期刊論文 前10條

1 周常春,鄧安福,張明義,干騰君,潘晉;水平荷載下群樁前后土抗力分布的數(shù)值分析[J];地下空間;2003年01期

2 吳昌將;張子新;;邊坡工程中抗滑樁群樁土拱效應(yīng)的數(shù)值分析[J];地下空間與工程學(xué)報;2007年S1期

3 包承綱,饒錫保;土工離心模型的試驗原理[J];長江科學(xué)院院報;1998年02期

4 唐志成;土工離心模型試驗原理及誤差問題[J];重慶交通學(xué)院學(xué)報;1989年04期

5 黃曉華;公路邊坡病害治理的輕型支擋結(jié)構(gòu)[J];重慶交通學(xué)院學(xué)報;1999年03期

6 韓理安,趙利平,韓時琳;樁側(cè)土抗力的群樁效率[J];長沙交通學(xué)院學(xué)報;1998年03期

7 李國亮;金福喜;張可能;;高壓雙液注漿與鋼管樁在深基坑支護中的應(yīng)用[J];廣東建材;2010年05期

8 章連洋;陳竹昌;;粘性土中P—y曲線的計算新方法[J];港口工程;1991年02期

9 馬白虎;;用鋼管樁加固失穩(wěn)邊坡滑坍堆積體的受力分析及運用[J];公路交通科技(應(yīng)用技術(shù)版);2010年05期

10 王士川,陳立新;抗滑樁間距的下限解[J];工業(yè)建筑;1997年10期

，

本文編號：1528467