a加筋土复合垫层处理软土地基施工技术

1、Good is good, but better carries it.精益求精，善益求善。a加筋土复合垫层处理软土地基施工技术a加筋土复合垫层处理软土地基施工技术加筋复合垫层处理软土地基施工技术摘要：山西某职业学院新校区学生公寓楼地基为软土地基，其承载力不能满足上部荷载的要求，采用加筋复合垫层进行加固处理。通过计算，及处理后的静载实验检测，地基承载力达到图纸设计要求，处理效果良好。关键词：加筋复合垫层 处理软土地基 施工技术1 引言位于太原市的山西某职业学院新校区学生公寓4号楼,地下一层地上六层剪力墙结构、钢筋混凝土筏片基础, 东西长57.8m，南北长16.3m,建筑面积5593.2 m2，

2、建筑总高度24.8m,室内外高差0.95m。筏片基础底面标高-3.85 m,-3.85m以上建筑总荷重111623.46 kN,设计基底压力为100 kPa。原设计用干振碎石桩复合地基处理，但经两个月的停歇恢复期后，检测复合地基承载力不能满足设计要求，需对地基进行补强加固处理。根据山西某职业学院新校区岩土工程勘察报告综合判定该场地属于中等液化地基，地基土分层及主要物理力学指标见下表：2砂石加筋复合垫层设计2.1设计原理、特点及方案。(1)设计原理。理论分析和实验观察都表明，土体受压时，在沉降的同时向两侧扩张，地基土破坏时，基础两侧的地表隆起，因此在基础下方存在着一个拉伸变形区域，其破坏与否与土

3、的侧向变形大小有关，允许的侧向变形愈小，它能承受的压力将愈高，所以，要提高土的承受能力，可以从设法减小其侧向扩张着手。如果将土工合成材料布置在这个区域，由于土体和加筋体共同承受荷载，使这种人工复合的土体可承受抗拉、抗压、抗剪或抗弯作用，从而提高地基的承载力、稳定性并减少沉降。加筋土正是利用了这一原理。在土体中的一定部位铺设水平方向的加筋材料，将土压实后，土与加筋材密切结合成一复合土体(加筋土)，当在复合土体的表面施加荷载，由于加筋材与周围土之间有较大的摩阻力(有时尚有咬合力)，限制了土的侧向变形，相当于在土体侧面上施加了约束力。从上面的道理可知，这种复合土体的承压能力理所当然地得到提高。 (2

4、) 砂石加筋复合垫层的特点：加筋的土体及结构属于柔性，对各种地基都有较好的适用性，因而对地基的要求比其他结构的建筑物低。加筋材与周围砂石之间有较大的摩阻力，从整体上限制地基土的剪切、侧向挤出与隆起，约束软黏土的侧向变形。能将上部建筑荷载均匀传递并扩散到下卧软弱土层上，扩散应力，使地基的附加应力降低，且分布均匀化，调整不均匀沉降，提高基础的整体刚度。能提高垫层的抗拉和抗剪性能，有效防止垫层的断裂和剪切破坏，增强砂垫层的整体性和刚度，能形成刚性较好的“梁板式”构件。减少占地面积，特别适合于在不允许开挖的地区施工。(3)设计方案。根据山西某职业学院新校区岩土工程勘察报告提示，该建筑基础土为中等液化地

5、基，其承载力较低，为消除地基的部分湿陷量，提高地基的承载力，经多种方案比选，采用7：3砂石加筋复合垫层处理地基，在砂石垫层内设置两层土工筋带，加筋带材料采用聚稀烃复合筋带，规格型号为TG5025型。网状双向布置，第一层土工带距基坑底面为900 mm，第二层与第一层间距为600 mm，每边超出基础边缘2m，端部筋带处理采用两层胞腔袋压住并回折伸入基础底部，回折长度不得小于3.5m。砂石垫层采用天然级配的砂卵石，底部设胞腔土工袋层。加筋复合垫层地基断面示意如图1所示。22通过计算砂石加筋复合垫层地基承载力值为2109 kPa，能满足规范和原设计对地基承载力要求。23沉降变形通过计算，地基最终沉降值

6、S=25.8mm，在规范和原设计允许的沉降范围内。3砂石加筋复合垫层施工对于软弱地基上的砂石加筋复合垫层施工，施工方法及工序至关重要。填土步骤不当，常会造成筋材的机械破损、产生不均匀沉降，甚至导致基础的破坏。3.1施工工艺基坑基底清理砂石材料拌合铺设胞腔袋第一、二层砂石垫层铺设及分层碾压、检测加筋带编制铺设第三、四层垫层及分层碾压、检测加筋带编制铺设第五、六层砂石垫层碾压找平、检测。 （1）、基础开挖至基底标高后，平整，对基坑进行钎探，记录，钎孔灌砂。（2）、原材料河卵石、毛砂进入现场后，经建设单位、监理单位验收并现场取样，送实验室复检合格后，用50装载机将砂石按7:3的比例拌合均匀。（3）、

7、人工将拌合好的砂石装入胞腔袋的袋子中，每袋装至三分之二即可，用封口机进行封口，将袋子运至基坑内，丁顺平放紧密放置，每排之间相互错开半个袋子，满铺一层然后将袋子之间的缝隙用中粗砂填满。见图：胞腔袋铺设（4）、拌好的级配砂石运至基坑内，在已铺设的胞腔袋上用轻型推土机或前端装载机填铺拌好的级配砂石，人工配合找平，随时用水准仪进行标高控制。在填铺第一层级配砂石时，一切车辆、施工机械只允许沿竖轴线方向行驶，不允许在级配砂石上回行。车辆、机械大小及重量均应限制，其形成的车辙不得大于78cm。铺完第一步砂石垫层后，用8吨的压路机进行碾压，碾压遍数不少于4遍，轮距搭接不小于50cm，碾压时应控制机械碾压速度，

8、碾压开始时宜用慢速。碾压找平后报监理单位及试验室现场取样，测试压实系数，待试验合格后进行下一步砂石垫层的铺设。第二步垫层重复第一步的做法。（5）、铺设加筋带，加筋带材料采用聚稀烃复合筋带，规格型号为TG5025型，中心距500mm，双向布置， 先铺设纵向的再铺横向，编制而成，应顺直、拉紧、平铺、避免折皱。加筋带材料不得直接铺设在碎石等坚硬的下承层上。应在加筋带和级配砂石之间铺设5cm厚的中、粗砂保护层，铺设加筋带的下承层表面应整平、压实，并清除表面坚硬凸出物。筋带的连接易用搭接法，最小搭接长度不小于1m，纵横交接处采用铁钉钉接法固定，铁钉使用前应进行防锈处理。端部筋带处理沿垫层周边每层布置胞腔

9、袋，每层筋带端头应回折，采用两层胞腔袋压住并回折伸入基础底部，回折长度不得小于3.5m。如下图： 加筋带编制加筋带压边（6）、加筋带应避免长时间暴晒或裸露，铺好筋材后，应在48小时内在其上进行下一步垫层铺设，杜绝一切施工车辆和施工机械行驶或停放在已铺好的加筋带上，级配砂石填铺前检查筋材有无破损、撕裂等现象。如发现有，应立即处理。铺放的筋材不得有褶皱，埴铺级配砂石前尽量将其人工拉紧。级配砂石填铺时应从中心向两侧对称填土，呈U形，利用填铺的级配砂石，使筋材保持受拉。卸级配砂石时要卸在前已铺好的面上，不要直接卸在筋材上。（7）、重复以上做法再铺设两层砂石垫层和一层加筋带，再铺设两层砂石垫层，最后一步

10、垫层必须保证平整度。具体做法见附图10to clean and repair, it is strictly forbidden to head reaches into the mechanical stroke range. 17th article: in overhead transmission line following work should blackout, cannot blackout Shi, due isolation protection measures, crane shall not in overhead transmission line followi

11、ng work, through overhead transmission line should will lifting arm falls, in overhead line side work Shi, regardless of in any situation Xia, lifting arm, and rope or weights, and overhead transmission line of recently distance should not is less than Xia table provides: transmission line voltage 1

12、000 v following 1-15 kV 20-40 kV 60-110 kV 220,000 v Allow minimum distances with the transmission line (m) vertical 1.5 level 1 1.5 2 3 4 5 6 4 6 18th: lamp voltage may not exceed 36 volts, when working in a damp place or metal containers, lamp voltage may not exceed 12 volts. 19th: pressure vessel

13、 should have a safety valve, pressure gauge, and avoid sun exposure, collisions, oxygen cylinders to prevent contaminated oil; of acetylene gas, LPG, must have a safety device to prevent tempering. 20th: x-ray and gamma-ray flaw detector operation area, non-operator, not allowed to enter. Article 21

14、st: corrosion, dust and radioactive and toxic work, protective measures are required, and to carry out regular inspection. Spider-man 22nd section III: Spider-man to regular medical examinations of the medical diagnosis, who suffer from high blood pressure, heart disease, anemia, epilepsy and other

15、discomfort in the Spider-man shall not engage in aerial work. 23rd: Spider-man dressed spirit, banned the wearing of hard bottom and easy slip-on shoe nail. 24th: Spider-man material stack stationary, tools should turn into a tool bag, transfer prohibited throwing of objects. 25th: in case of bad we

16、ather (such as wind in the above grade) construction safety, prohibition of the open air, lifting and piling. 26th article: ladder shall not deficiency document, no padded using, ladder cross document spacing to 30 cm suitable, using Shi top to tied prison, bottom should take anti-sliding measures,

17、single ladder and ground angle to 60 degrees suitable, ban II people while in ladder Shang job, as needed received long using, should lashing firm, people Word ladder in end of feet pulled prison, in channel at using ladder, due guardianship or set fence. 27th: no security measures, prohibited in hi

18、p joints, supports, trusses of the roof truss cantilever beams, and choose the frame and half fixed widget or job to walk on, Spider-man and the ground . Nine, ten basic security to prevent vehicle damage claim 1, without legal training of qualified certified personnel not familiar with vehicle perf

19、ormance is not driving a car. 2, should insist on doing defense work, vehicle brake, Horn, steering systems, lighting and other safety components such as poor are not allowed out of the car. 3, dump truck, dump truck car hop is strictly prohibited, prohibited goods mixing, loading of vehicles should

20、 not overload,ích zaízení, budov a konstrukcí, tanky a jiné zásuvky prmyslové vody, krom ustanovení vodu tak, by mlo být instalováno v oblasti s vodou k utsnní vrtu, uzavírací ventil, aby se zabránilo velké mnoství holav

21、ých a výbuných materiál do kanalizace. 9. pouití v holavých, výbuných plyn pojistný ventil a vtrací potrubí, je nutné export trubice je umístn mimo a vyí ne 2 metry nad budovou. (B) pouívání ohn, ohe (viz systé

22、m správy práce) (c) poární zaízení a organizací 1. realizace "prevence první a integrované prevence" ohe politiku, pijmout moderní technologie poáru a výbuchu prevence a pomoci, provádní ízení podle cíl. 2

23、. zízení vedení spolenosti a vedoucí jednotlivých oddlení Poární bezpenost výboru, workshop zaloena poární ochrany, vedoucí skupiny a nastavit dobrovolných hasi. 3. spolenost útvaru ochrany spotebitele na plný úvazek has

24、ii, hasii formulovat plán protipoární prevence a akní plán, provádní ízení podle cíl, pravideln provedení publicitu poární prevence a vzdlávání a kolení, v kombinaci s oekávané poární cviení

25、. 4. soubor stacionární ohn uvnit spolenosti zaízení, protipoární zaízení musí být v Správa slueb, rozvoj provozní postupy a systémy ízení. 5. poární zaízení na serveru nastavit jasné, pístup k p

26、ohodlné a bezpené místo, pravidelné kontroly údrby, "ti" (to je, pevné, fixní typ a mnoství, podle odborník), a nemá nikdo nenapadal, pachatel dle systému ke zpracování. 6. vechny holavé a výbuné látky ve

27、spolenosti a potenciální ped poárem a výbuchem nebezpené výroby, skladování, prodej a pouívání procesu a jeho související vybavení, písné ízení. 7. kdy je ohe, pole táby okamit uspoádejte do boje s oh

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29、gulations. Six is strictly your presentation published strictly according to the regulations. Seven is strictly thrift, required the use of vehicles and office space and corporate hospitality. 3, change the style. Propaganda and ideological work of the new situation and new requirements of the new t

30、asks, had done a lot of fruitful work, has made many achievements, but further closer to the grass roots, close to reality, close to the masses and also inadequate innovation must continue to improve. Second, the "four winds" some outstanding issues 1, oppose formalism. One theory is that

31、he didn't, with less close contact. Theoretical study of consciousness is not high enough, system performance is not strong enough; more passive learning, active learning few generalities and learn more, delving into less. Especially based on rational thinking on major issues, applying theory to

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33、ess supervision. Propaganda and ideological work is the objective, which needs to keep the continuity efforts deployed, but stressed in the work time, less supervision. For example, color weekends in the summer theatrical activities, city square performances, urging townships, communities and rural

34、areas shows the implementation is inadequate, insufficient cultural an educational role to play. Third base enough, master grass-less real. Propaganda and ideological work in the new situation of characteristics and regularity of enough, deep enough for grass-roots public opinion Dynamics survey, fo

35、r grass-roots typically drive less. For example, rural culture team active, . I'm not actively take the initiative to take up, the lack of spirit of daring to, resulting in some job had a lot of power, but no tangible results. Third, innovation, lack of motivation. Emancipation did not end, innovation does not exist. In practical work, not your head, previous work experience, lack of innovation initiatives, stud