x膨胀土路基石灰改良施工工艺研究.doc

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1、ocusing on ways and means of improving and upgrading work, further development of three to split. (A) fully grasp no unauthorised created. The township no unauthorised created the existing building one household, one document survey and file storage work must be unconditional and full coverage. Main

2、 corridor leading to the town (road, river) village, the Central built-up area of the town on both sides must be to create a no unauthorised village. According to five hundred villages created and shanty towns, villages, old houses, reconstruction of old plant, expand create, upgrading creates files

3、, the real no unauthorised village created into the benefit of the people of very good thing. (B) to strictly manage count as unauthorised controls. Promoting the new control work to move the center of gravity, management measures to the front, and earnestly pipes effectively. A strict new unauthori

4、sed network responsibility. Sectors such as land, housing and basic stations (stations) and the Township of grid accountability mechanisms must be strictly in accordance with the new regulatory requirements, effective implementation of the area of responsibility of the new inspections, suppression,

5、demolition work to ensure that the new zero tolerance. Second, public security, water, electricity, water, oceans and fisheries, tourism collaboration, market supervision departments should strictly enforce the illegal construction of disposal of relevant provisions of the regulations, effective ful

6、filment of responsibilities, particularly in electricity and water supply, and other units may not be new illegal buildings to supply water and electricity supply. While more regulation to prevent personal privacy violations. Illicit trading in illegal construction in the Ministry of public security

7、 sector to strictly from the blow. Three is to create additional offence reporting system of incentives. According to building law and covers an area of nature, to report timely degree divided report grade, effective after the removal of certain incentives. (C) integrated implementation , building d

8、emolition, modification, use combination. Demolition is the means and purpose built is. To adhere to the building demolished, combination of construction and demolition waste, demolished with combined efforts to improve the scientific level of three to split; second, we must pay attention to three t

9、o split and five hundred and five water treatment, three of the four sides, the shackDistrict transformation, and dangerous old room transformation and two road sides, series work organic combined up, active do River, and along demolition work, and manpower advance village in the, and old residentia

10、l demolition work, to improved masses housing conditions and live environment; three to put three modified a split as traditional low, and small, and bulk industry structure transformation upgrade of important initiatives to caught, speed up advance industry Park, effective optimization park environ

11、ment 南京交通职业技术学院毕业论文 题目: 膨胀土路基石灰改良施工工艺研究 院 系: 路桥与港航工程学院 专业名称: 道路桥梁工程技术 班 级: 112014 学 号:11201414 姓 名: 朱棒棒 指导老师: 赵艳艳 完成时间: 2014 年 05 月 07 日to produce white smoke, so twice, cold. Cold solution moves into the 50mL or 100mL in the bottle, washed nitrogen bottle wash solution into the volumetric flask, co

12、ol, such as water to the scale, and mix. Sizing 10mL 1g a solution of the specimen, sulfate 1mL. Get and digest the samples the same amount of nitric acid a mixture of perchlorate with sulfuric acid, by the same method of reagent blank. 12.1.2 vegetable, fruit, weighing 2500g or 50.00g wash in a hom

13、ogenate samples placed in a 250mL500mL nitrogen bottles, adding seed glass beads, 10mL15mL, nitric acid a mixture of perchlorate, according to 12.1.1 place for a moment . . action according to law, but a constant volume of solution after each 10mL 5G sample, sulfate . 12.1.4 containing alcohol sex b

14、everage or containing carbon dioxide beverage: draw 10.00mL or 20.00mL sample, placed 250mL500mL set nitrogen bottle in the, Addend grain glass beads, first with fire heating removed ethanol or carbon dioxide, again added 5mL1OmL nitric acid-perchlorate mixed liquid, mixed uniform Hou, following by

15、12.1.1 since placed moments. up law operation, but set capacity Hou of solution each 10mL equivalent to 2mL sample. 12.1.5 foods high in sugar content: weighing 5.00g or 10.0g specimens placed in the 250mL500mL nitrogen bottle, add a little water to wet, the augend seed glass beads, 5mL10mL, nitric-

16、perchloric acid after mixing, shake well. Slowly add 5mL or 10mL sulfate, after treating the ease stops foaming, low heat, slowly heating (sugar easy charring), continue along the wall added nitric-perchloric acidand improve idle land of utilization, real achieved environment improved and productivi

17、ty development mutual promoting total win. Five, firmly implement, promoting work ahead, to create highlights. Third deployment, implementation of seven, then it is imperative to strengthen responsibility and improve the mechanisms and implementation. All localities and departments must be convinced

18、 that goals, going all out, mustering spirit, work together to ensure that this years objectives carry out tasks, at the forefront. First, we must strengthen the leadership to implement. Departments at all levels should always work and rural five water treatment, three to split in an important posit

19、ion, and carry the main responsibility, main leader personally, leaders arrested and layers of responsibility rank transmission pressure established hierarchical accountability, and work together to promote the work of the mechanism, a concerted effort pay attention to implementation. County nongban

20、, flood, three to one down to further play a leading catch total, integrated and coordinated role of all kinds is long, Sheriff Inspector to effectively fulfill their responsibilities, formed the alignment on the fire line and management a lively situation. Second, we must strengthen the test implem

21、entation of the Governor. Role play the Governor got the baton, for agricultural and rural focus and five water treatment, three to split work, refine improve assessment methods and evaluation system, accurate assessment. Combined with dare play, tree benchmark style building five major operations,

22、carry on and gain firsthand experience of supervision, in particular, to strengthen the focus on the long signs go left, names such as supervision, urged all levels longer on duty in place. Through the supervisory assessment, to promote habits, stimulating power. Third, we must strengthen implementa

23、tion style. Departments at all levels to work in rural areas and five water treatment, three to split as training cadres for major platforms, compete against large examination room, inspection cadres work performance of the ring, water control and the Japanese pulled a workout, training, discovery a

24、nd selection of cadres. Than good catch up, first to excellence-oriented. Party members and cadres at all levels must adhere to the rural, water control and the Japanese pulled a grass-roots, put down the shelf, leaned pragmatic style, the spirit of play, become a benchmark model. Four, we must stre

25、ngthen propaganda implementation. Comprehensive utilization of micro-credit, micro-blogging, new media, mining, summarizing, good publicity work in the countryside and five water treatment, three to split advanced models, point to gather positive energy for the community to see the results of our wo

26、rk in time, increase public awareness, participation rates, satisfaction and support. Play gongqingfu, a mass organization and grass-roots such as schools, communityThe role of 目 录摘要11前言12膨胀土概述及石灰改良机理12.1膨胀土的特性分析12.2膨胀土的危害性22.3 我国研究现状22.4 石灰改良膨胀土的机理32.4.1离子交换作用32.4.2碳酸化作用32.4.3凝硬反应32.4.4胶结作用43石灰改良膨胀

27、土施工流程43.1 施工准备43.2 基底处理及焖灰43.3 粉碎拌和53.4 稳压整平53.5 碾压53.6 养生53.7 接头处理64施工中应注意的问题65工程实例7结束语7参考文献7致谢8膨胀土路基石灰改良施工工艺研究摘要:膨胀土路基在实际公路、铁路建筑施工中由于其固有的结构特性而容易导致险情发生,因此有必要对其施工工艺进行研究。本论文简单的叙述了膨胀土的特性和研究现状,分析了其危害性着重的介绍了石灰改良膨胀土的机理以及其施工流程和注意事项。关键词:路基;膨胀土;石灰改良;施工工艺1前言我国的国土辽阔且地质情况复杂,各省市的情况各有不同。这对工程建设无形中增大了很大的难度。本文利用河南省

28、商丘市睢阳区南京西路新建工程对石灰改良施工工艺进行分析,该工程路基出现大面积的膨胀土。膨胀土的特点是遇水后强度十分低,失水后强度十分高。而石灰就有吸水的功效,为更好地发展城市经济,在选择改良方案上保证其效果的情况下应当考虑其经济效益,而采用石灰改良造价较低,对施工条件和施工环境要求较低,故石灰改良使用普遍。本文就是从施工工艺着手研究,目的在于改进施工工艺,使得石灰改良这个方法更加高效。2膨胀土概述及石灰改良机理2.1膨胀土的特性分析所谓膨胀土是一种对环境湿度变化敏感,由强亲水性矿物蒙脱石和伊利石等组成,具有多裂隙性、强胀缩性和强度衰减性的高塑性粘土。在自然状态下膨胀土多呈现硬塑或坚硬状态,其颜

29、色多为黄、褐、灰白等颜色。在一般情况下,膨胀土强度较高,压缩性较低,容易被误认为是性能良好的地基土。但当土中含水量变化时,膨胀土有发生胀缩变形的特性对建筑物具有相当大的破坏性。因此,膨胀土是一种在公路建设中不可忽视的不良地基土。2.2膨胀土的危害性膨胀土是在自然地质过程中形成的一种多裂缝并具有显著膨胀特性的土体,由于其不良的工程性质,在工程界被认为是隐藏的地质灾害,对工程结构具有严重的破坏作用。特别是对高等级公路路基工程和大型结构物所产生的变形破坏作用,往往具有长期、潜在的危险,由于对膨胀土膨胀能力估计不足而造成公路病害的损失是相当惊人的。膨胀土地区的公路发生的病害主要有以下几个方面:(1)沉

30、陷变形。膨胀土初期结构强度较高,施工时不易粉碎及压实,路堤建成后由于大气物理风化作用和湿胀干缩效应,土块崩解,在路面和路堤自重及汽车荷载作用下,路堤易产生不均匀下沉,路堤愈高,沉陷量愈大严重时可使路面变形破坏。(2)滑坡。滑坡具有弧形外貌,有明显的滑床,滑床后壁陡直,前缘平缓,主要受裂隙控制。滑坡多呈牵引式出现,具叠瓦状,成群发生。一般滑体厚为13m,多数小于6m。滑坡与大气风化作用层深度、士的类型、土体结构较密切,而与边坡的高度无明显关系。(3)溜塌。边坡表层、强风化层内的土体吸水过饱和,在重力与渗透压力的作用下,沿坡面向下产生流塑状溜塌。溜塌多发生在雨季,与边坡坡度无关。(4)纵裂。路肩部

31、常因机械碾压不到,填土达不到要求的密实度,后期沉降量相对较大,加之路肩临空,对大气风化作用特别敏感,干湿交替频繁,肩部土体收缩远大于堤身,故在路肩上常发生顺路线方向的开裂,形成数十米至上百米的张开裂缝,缝宽约24m,大多距路肩外缘05 1Om。(5)坍肩。路堤肩部士体压实不够,又处于两面临空部位,易受风化作用影响而导致强度衰减。当有雨水渗入时,特别是当有路肩纵向裂缝出现时,在汽车动荷载作用下,很容易发生路肩坍塌。塌壁高多在1Om以内,严重者可大于1Om,常发生在雨季。2.3 我国研究现状随着我国经济建设的发展,膨胀土的研究越来越引起国内岩土工程界的重视。在20世纪50年代初期,我国在修建成渝铁

32、路工程中,才首次遇到成都粘土膨胀性危害的问题,从而拉开了我国膨胀土研究的序幕。20世纪70年代中期,我国开展了大规模的膨胀土普查工作,建立了科学研究的试验基地,进行了卓有成效的研究,取得了一定的科研成果和工作经验。1989年我国制定了膨胀土地区建筑技术规范,1990年在成都市召开了全国首届膨胀土科学研讨会,并出版了论文集。会议对我国膨胀土的研究现状、膨胀土的工程性质和膨胀土处理技术及工程应用进行了广泛的研讨。1994年在武汉召开了“中加非饱和土学术研讨会”标志着我国膨胀土理论研究已经达到了一个新的高度。2.4 石灰改良膨胀土的机理石灰石是一种无机的胶结材料,既能在空中硬化,也能在水中硬化。石灰

33、的性质取决于活性CaO和MgO的含量,其含量越高,活性越大,胶结能力越强。石灰改良膨胀土的过程既有物理作用,又存在化学反应,两者共同作用促使土体性质发生根本变化。2.4.1离子交换作用石灰加入土中后,在水的参与下离解成Ca和OH离子,Ca与Na、K发生离子交换,使胶体吸附层减薄,电位降低,使膨胀土分散性,坍塌性、亲水性和膨胀性降低,塑性指数下降,使黏土胶体絮凝,土骨架形变降低,使石灰土获得初期的水稳定性。2.4.2碳酸化作用Ca(OH)2和Mg(OH) 2在土中还会不断和空气中的二氧化碳反应,生成具有较高强度和水稳定性的CaCO3和MgCO3坚硬固体颗粒。由于CaCO3对土体的胶结作用使得土体

34、加固,形成石灰稳定土,此作用过程相当长,形成石灰土的后期强度。2.4.3凝硬反应石灰加入土中后,经过物理作用和化学作用,石灰改良土发生团聚,随之生成胶凝物,形成凝胶团聚结构。随着龄期的增长,棒状及纤维状结晶体生成,并不断生长,形成了结晶体的网状结构。随着龄期的继续增长,胶凝结构层加厚,结晶体的网架加密,形成了胶凝结晶的网状混合结构。2.4.4胶结作用这种作用对石灰改良膨胀土的强度提高其决定性作用。在这个过程中适量的石灰和水可同土中大量存在的硅、铝或者同时作用,产生较强的黏结物质,还会提供一种高碱性的环境。在这种高碱性的环境中,主要生成氢氧化钙和氢氧化铝,结果将使土的强度有大幅的提高,土的结构也

35、发生大的变化。火山灰反应是土中的活性硅、铝矿物在石灰的碱性激发下解离,在水的参与下与Ca(OH) 2反应生成含水的硅化钙和铝酸钙等胶凝物。这些胶凝物逐渐由凝胶状态向晶体状态转化,使石灰改良土刚度不断增大,强度和水稳性不断提高。3石灰改良膨胀土施工流程3.1 施工准备施工前照设计要求对原地面进行处理。根据现场以及施工队工作情况对全线进行合理分割作业段,每一工作100200m为宜。对欲要使用的生石灰需要检测有效钙镁含量,一般钙镁含量大于等于70%。根据填土高度、分层填筑厚度以及设计要求划分出每个段不同压实度和灰剂量部位的填筑层数。配备机械为振动压路机YZ-18J型1台、振动压路机XS202J型2台

36、、振动压路机徐工XS222J型1台、胶轮压路机XP260型(26T)1台,胶轮压路机YL16型(16T)1台,卡特挖机一台,三一挖机一台,现代-7一台,现代-9一台核查进场机械型号,明确进场的机械所对应的工作效果以及预期效果。3.2 基底处理及焖灰 因是设计变更缘故所以基底标高以及松坡高度无需再进行控制。所以开始即对原有的基底用挖机进行翻挖,然后用旋耕机进行打碎。利用震动压路机进行静压一遍。然后进行焖灰,在整平土方上用石灰划石灰线格,根据每车生石灰的吨位,计算每车石灰的摊铺格数,由现场施工人员负责安排倒石灰,由平地机负责整平,在路线中央形成宽两米,高约20cm的长方体俗称“码方”。用挖机配合人

37、工进行布灰,均匀撒在整平后的土方上面。焖灰时间要维持在24h。 3.3 粉碎拌和利用大型旋耕机进行拌合,一般拌合深度要求达到25cm。由两边向中间进行拌和粉碎,拌和时配备人工按照逐桩桩号对已粉碎过段落用铁锹进行挖开口径大约的30-40cm的孔直至挖到旋耕机未翻打到处,以便于机械手调节拌和深度。于此同时应要捡出大于5cm的土块,特别是要捡出在膨胀土形成过程中生成的结核疆石,在此同时该路段要进行灰剂量检测,测定加灰是否足够。3.4 稳压整平利用震动压路机先对其进行静压一遍,利用平地机对其进行初评。根据河南当地该土质特性控制松坡高度为4cm。利用测量手段将其标高控制然后平地机进行终平。3.5 碾压碾

38、压采用振动式压路机和1821 三轮静态压路机联合完成。整平完成后,首先用振动压路机由路边沿起向路中心碾压(超高段自内侧向外层碾压),有超高段落由内侧起向外侧碾压,碾压采用大摆轴法,即全轮错位,搭接1520 厘米,用此法震压68 遍,下层压实度满足要求后,改用三轮压路机低速1/2 错轮碾压23遍,消除轮迹,达到表面平整、光洁、边沿顺直。路肩要同路面一起碾压。碾压时,如出现表层含水量太少而松散的现象,可适量补充洒水并在表层收干不沾轮后再碾压。如出现“弹簧”等局部含水量过多现象,则挖出“弹簧”土,用合格土料回填并补充压实。由于该土质经过风化容易起皮,故在三轮和震动配合碾压后计算依据最佳含水量按喷洒面

39、积计算所需水量进行均匀喷水,利用皮轮压路机在后面进行収表。碾压结束后对该路段进行压实度检测。3.6 养生不能及时覆盖上层结构层的灰土,养生期不少于7 天,采用洒水养生法,养生期间要保持灰土表面经常湿润。洒水期间应该注重洒水的均匀性,必要时可以配备人工进行掌控喷洒。养生期内应封闭交通,除洒水车外禁止一切车辆通行。有条件的对7 天强度确有把握的,灰土完成后经验收合格,即可缩短养生期进行下道工序施工,但一旦发现灰土强度不合格,则需返工处理。 3.7 接头处理压完毕的石灰土的端头应立即将拌和不均,或标高误差大,或平整度不好的部分挂线垂直切除,保持接头处顺直、整齐。下一作业段与之衔接处,铺土及拌和应空出

40、2 米,待整平时再按松铺厚度整平。桥头处亦按上述方法处理,铺土及拌和应空出2 米,先横拌2 遍再纵拌,待整平时再按松铺厚度整平。4施工中应注意的问题(1) 施工期间为保证工程质量,所以要做好临时排水措施。路基两侧设置好临时排水沟,设置必要的边坡急流槽,以保护边坡防止雨水冲刷。(2) 为了防止雨水大量渗入土层迫使石灰失效,所以如果基底碾压前降雨,则应快速整平碾压1遍。(3) 若每层土方碾压完毕并经验收合格后,应立即进行下层土方的填筑施工,以防碾压好的土层失水干裂。(4) 碾压成型的路基越冬时,要采取覆土保温措施,覆土厚度不小于25cm,压实度不小于80%。过薄或不经压实的覆土经过风化后无法进行有

41、效保护。(5) 施工工序应紧密衔接及时施工,避免接缝引起基底不够平整影响路面平整度。施工中应严格控制灰剂量、石灰的均匀性,避免上层路面出现裂缝褶皱。(6) 在碾压前用平地机终平一次,使其总想顺从,路拱和横坡符合要求,终平应该仔细局部高出的刮出清扫到路外,低洼处不应进行修补等到下层进行补充。(7) 两工作段的搭接部分,应采用对接形式,碾压仍然用压路机沿着垂直路基中线方向横向碾压,然后再纵向碾压。(8) 养生期间切忌除洒水车外车辆在上面通行。5工程实例河南省商丘市睢阳区南京西路市政工程。本工程西起梁园路,东至平原路,全长2985.514m。其沿途相交道路11条,其中金桥路、平原路为现状路,其余均为

42、规划路。道路红线宽度为60m,四幅路型式。中分带宽为2m,路面横坡为1.5%。在施工路基基底处理过程中,发现基底以下5-40cm处出现大面积膨胀土土层,压实度无法达到要求且土方表面出现起皮现象严重。按照常规的作业无法达到设计要求的压实度,且碾压过后表面会出现翻浆,“弹簧”面积较大,上报业主需要进行设计变更,结合项目部和业主专家以及设计专家会审,该工程为市政工程等级较低排除成本较大的湿喷桩等方法,而灰土造价较低且工作性能较优可以达到解决问题的目的。测定土质的含水量以及土质后决定对其进行8%的灰土处理,解决了该工程难题。经过改良后该工程压实度和平整度均通过要求。有效改善弱膨胀土的工程性质,完全满足

43、路基填筑的要求。掺加石灰之后,液塑限得到了很好的改善。工程的膨胀土得到了根本性的改变,利用石灰改良施工条件简单方便造价较低避免了大量的资金投入。使粘粒土的含量大大降低,同时CBR值的得到提高。但是石灰施工的同时对周围的土地、空气污染较大。由于市政工程周围居民较多为该地区的日常生活带来了不便。结束语膨胀土在我国遍布比较广泛,作为建筑行业的一名技术人员对于该土质的研究任重而道远。通过对该施工工艺研究,为施工企业谋求了利润,有助于我国经济的发展,质量良好的交通工程便利了人民的生活,作为一名路桥人应不断的去探索去创新我们的施工工艺,谋求更加完美的施工工艺。为社会主义现代化建设出力。参考文献1陈家饶膨胀土路基石灰改良施工工艺研究 ,经营管理者第17期 2010.9. 2佟辉高速公路路基膨胀土填筑工艺研究,长安大学 2012.10.3徐淳美膨胀土路基石灰改良施工工艺试验研,西安交通大学2005.9. 致谢感谢论文老师的指导和建议,使我的论文得以完成。帮助我顺利完成了大学生活的最后一门课程。7

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