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1、不良地质钻孔灌注桩施工要点摘要：钻孔灌注桩施工是桥梁下部施工中非常重要的控制要点，桩基础的质量直接影响到桥梁施工和通车后的使用质量。在我国长江中下游地区进行桥梁施工时，因为此区域属冲积平原，地质以表面粘土下面砂性土为主，有些地区粘土层非常薄，而且下部的砂性土层构造和组成非常复杂，给我们的桥梁施工提出了相对严峻的实际问题，值得我们研究。关键词：桥梁 不良地质 桩基础 一工程概况：泰州长江公路大桥位于泰州、镇江和常州交界处，东距江阴大桥57公里，西距润扬大桥66公里，泰州长江公路大桥为主跨1080m的三塔悬索桥，桥跨布置为390+1080+1080+390m，主桥桥宽33m，设计车速100km/h
2、，全线长为62.088km。夹江大桥位于江苏省扬中市南侧夹江段，上游距扬中大桥约8km，下游距扬中二桥约16km，北接泰州长江公路大桥扬中接线段，南联镇江新区。夹江大桥右汊桥及引桥全长1635m，桥跨布置为(840)+(840) +(87.5+2125+87.5)+（730) +（630) +（630)1635m；镇江岸引桥段基础采用1.2m的钻孔灌注桩，共计156根；小炮沙岛引桥段采用1.5m的钻孔灌注桩，共计180根；右汊桥主桥段基础采用1.5m、2.0m两种桩径的钻孔灌注桩,其中43#、47#墩采用1.5m 的钻孔桩，共计24根，44#墩46#墩采用2m 的钻孔桩，共计57根。全桥各类钻
3、孔桩共计417根，最大桩长为96m。二地质情况简介：根据实际施工中发现总结，本地区的地表粘土层非常薄，从原地面往下1.5米即止，再往下就是大约2米厚的淤泥质粉粉质粘土，随后是往下即是透水性，流动性非常强的粉砂、细砂、中砂组成的液化砂土，这些地层情况不规则，不连续，变化多端。在多雨的夏季，从地表往下挖1米多深的小坑即如小泉眼般渗水不止，随后流砂层被水冲出，很快便会发生坍塌。在这种地质条件下如何能保质保量的完成下部桩基施工就成了摆在大家面前的课题。经过大家多次讨论研究，并结合工地实际施工情况，总结出一些应对这些不良地质情况的施工经验和方法，在这里罗列出来供大家参考讨论。三具体施工要点控制1.护筒埋
4、设，护筒埋设前先平整场地，如场地泥土松散应进行夯实， 护筒采用5mm厚钢护筒，坚实、不漏水，内径比桩径稍大2040cm。护筒中心竖直线应与桩中心线重合，平面允许误差为30mm（测量监理要求），竖直线倾斜不大于1%，护筒顶端宜高出地面0.3m，当孔内有承压水时应高出稳定后的承压水和最高水位2.0m以上。因为此地区的特殊情况，护筒一般埋深为4米，以防止护筒周围塌陷。2钻机就位 ， 钻机安装平正、稳固，确保施工中不沉陷、倾斜、移动。 3.泥浆制备， 介于本地区的特殊地质情况，我们对钻孔使用的泥浆的制备也进行了严格的要求，泥浆的各项指标如下：比重：1.061.10g/cm3粘度：一般地层1620S；松
5、散易坍地层1828S；胶体率：95%含砂率：4%失水率：20ml/30mim酸碱度: 810钻孔泥浆选用如果粘土造浆不能满足要求，则须选用不分散、低固相、高粘度的PHP优质膨润土化学泥浆。泥浆由优质膨润土、碱（Na2CO3）、羟甲基纤维素（CMC）和聚丙烯酰胺（PHP）等原料组成。 4.钻孔过程当中的控制 钻孔桩采用GPS1800型、GPS2000型回旋钻机,开钻时应低档慢速，空钻向孔中注入清水、原土造浆，按土质情况进行正常钻进，在粘土中钻进，宜用中等钻速，大泵量，稀泥浆的操作方法。砂土中钻进，宜采用低档慢速，大泵量，稠泥浆的操作方法。缩颈时，应在缩颈处来回扫孔，塌孔时投入粘土块，使钻头慢速不
6、进尺，并降低泥浆输入速度和数量进行护壁，然后慢速通过，当空倾斜和孔径不规则时，可反复提钻。当钻孔过程漏浆时，应立即在护筒周围回填粘土夯筑密实、增加护筒沉埋深度、适当减小护筒内水头高度、增加泥浆相对密度和粘度、倒入粘土使钻锥慢速转动、增加孔壁粘度质土层厚度等措施。当遇到承压水时，应加大泥浆比重（在泥浆中加入褐煤粉、褐铁矿粉或重晶石粉）到大于压水水头压力为止。正常钻进时，要勤捞渣、勤测泥浆比重粘度和含砂率，并及时填写钻孔记录。5.成孔后清孔的控制：用正循环钻孔终孔后，均采用换浆清孔。具体办法是停止进尺，将钻头提离孔底1020cm空钻，并保持泥浆循环,加入比重1.051.2的泥浆，把浮渣较多的泥浆从
7、孔中换出，直至达到清孔后沉渣厚度符合设计图纸要求厚度（不得大于20cm）。换浆后钻孔排出的泥浆性能指标应达到：含砂率小于2%比重1.051.2粘度1622Pa.S6.水下混凝土灌注注意事项：砼灌注前，要办好隐蔽工程施工各项检查签证，施工过程中要认真填写施工记录表和施工记录。砼灌注工作应连续不间断进行，万一发生砼灌注中断事故，应根据导管的埋置深度，间断、少量提升导管，并立即排除故障。泡沫隔水栓塞应进行通过检查。砼灌注是一个完整、连续、不可间断的工作，灌注工作开始前，机械管理人员和负责司机应对砼灌注所使用的全部机械进行维修、保养，保证机械在施工过程中正常运转。砼灌注工作是桩基施工的关键工序，应有专
8、人负责指挥、协调。水下混凝土灌注完毕，对混凝土的拌和、运输、灌注等所用设备进行清点和清洗，并妥善保管备用。参考文献JTJ041-2000公路桥涵施工技术规范姚玲森：桥梁工程，人民交通出版社，1985（英文版 ） Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementatio
9、n in accordance with the rules and discipline to manage the party, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high st
10、andard; around the party discipline, disciplinary ruler requirements, listed as negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the bottom line . Here, the main from four square face two party rules of interpretation: the first part introduces t
11、wo party Revised regulations the necessity and the revision process; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key
12、problems; the fourth part on how to grasp the implementation of the two regulations of the party. and revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines and column 1 by 2015
13、 to strengthen party laws and regulations focus. Two party regulations revision work lasted a Years, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow th
14、e correct direction, grasp the limited goals, adhere to the partys leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the and , reflects the partys 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experien
15、ce of studying and implementing the General Secretary Xi Jinping series of important speech, reflects the partys eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of in based on revised, the promulgation and implementation of January 2010, to strengthen th
16、e construction of the contingent of leading cadres play an important role. But with the party to manage the party strictly administering the deepening, has not been able to fully meet the actual needs. Content is too complicated, eight prohibition, 52 are not allowed to hard to remember, and also di
17、fficult to put into practice; the second is concisely positive advocated by the lack of prohibited provisions excessive, no autonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinary regulations repeat and Criminal law and other laws and regulat
18、ions repeat; the fourth is to clean the theme is not prominent, not for the existing problems, and is narrow, only needle of county-level leading cadres above. is in 1997 based on revision, in December 2003 the promulgation and implementation, to strengthen the construction of the party play very im
19、portant role. Along with the development of the situation, which many provisions have been unable to fully meet the comprehensive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal law and other countries laws and regulations Repetition; two is th
20、e political discipline regulations is not prominent, not specific, for violation of the party constitution, damage the authority of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main discipline for the leading cadres, does not cover all Party memb
21、ers. Based on the above situation, need to and the two is likely to be more relevant regulations first amendment. By revising, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of Party members and cadres of the party constitution of party compa
22、sses party consciousness. (II) two party regulations revision process the Central Committee of the Communist Party of China attaches great importance to two regulations revision . Xi Jinping, general books recorded in the Fifth Plenary Session of the eighth session of the Central Commission for Disc
23、ipline Inspection, on the revised regulations made clear instructions. According to the central deployment, the Central Commission for Discipline Inspection from 2014 under six months begin study two regulations revision. The Standing Committee of the Central Commission for Discipline Inspection 4 r
24、eview revised. Comrade Wang Qishan 14 times held a special meeting to study two regulations revision, amendment clarifies the direction, major issues of principle, path and target, respectively held a forum will listen to part of the province (area) secretary of the Party committee, Secretary of the
25、 Discipline Inspection Commission, part of the central ministries and state organs Department The first party committee is mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members. Approved by the Central Committee of the Communist Party of Ch
26、ina, on 7 September 2015, the general office of the Central Committee of the Party issued a notice to solicit the provinces (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commissions of the Party (party), the General Political Department of t
27、he military, every 3 people organization of Party of two regulations revision opinion. Central Commission for Discipline Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In October 8 and October 12, Central Committee Political Bureau Stand
28、ing Committee and the Political Bureau of the Central Committee After consideration of the two regulations revised draft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two laws amendment concentrated the wisdom of the whole party, embo
29、dies the party. Second, and revision of the basic principles of two party regulations revision work and implement the partys eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and General Secretary Xi Jinping important instructions on the revised
30、and , highlighting the ruling party characteristics, serious discipline, the discipline quite in front of the law, based on the current, a long-term, advance as a whole, with Bu Xiuding independent and . Main principle is: first, adhere to the party constitution to follow. The constitution about dis
31、cipline and self-discipline required specific, awaken the party constitution of party compasses party consciousness, maintaining the authority of the constitution. General Secretary Xi Jinping pointed out that no rules, no side round. Party constitution is the fundamental law, the party must follow
32、the general rules. In early 2015 held the eighth session of the Central Commission for Discipline Inspection Fifth Plenary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow the general rules, but also the general rules. the revision of the
33、 and is Method in adhere to the regulations established for the purpose of combining rule of virtue is to adhere to the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and party rules the sense of discipline, the party constitution abo
34、ut discipline and self-discipline specific requirements. 4 second is to adhere to in accordance with the regulations governing the party and the party. The Party of rule of virtue de, mainly refers to the partys ideals and beliefs, excellent traditional style. The revised the closely linked to the s
35、elf-discipline, insisting on the positive initiative, for all members, highlight the vital few, emphasized self-discipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised Ji method separately, Ji, Ji Yan to Method, as a negative list,
36、 emphasizing the heteronomy, focusing on vertical gauge. Is this one high and one low, a positive reaction, the strict party discipline and practice results transformation for the integration of the whole party to observe moral and discipline requirements, for the majority of Party members and cadre
37、s provides benchmarking and ruler. Third, insist on to. In view of the problems existing in the party at the present stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to make clearly defined, especially the partys eighteen years strict
38、political discipline and political rules, organization and discipline and to implement the central eight provisions of the spirit against the four winds and other requirements into Disciplinary provisions. Not one pace reachs the designated position, focusing on in line with reality, pragmatic and e
39、ffective. After the revision of major changes, major changes in the and modified and needs to grasp several key problems (a) adhere to according to regulations governing the party and party with morals in combination, for at the present stage, the leadership of the party members and cadres and Party
40、 members in existing main problems of self-discipline, put forward principles, requirements and specifications, showing Communists noble moral pursuit, reflected at all times and in all over the world ethics from high from low 5 common requirements. One is closely linked to the self-discipline, remo
41、val and no direct relation to the provisions of . the second is adhere to a positive advocate, eight prohibition 52 are not allowed to about the content of the negative list moved into synchronization amendment . Three is for all the party members, will apply object from the leadership of the party
42、members and cadres to expand to all Party members, fully embodies the comprehensive strictly required. The fourth is prominent key minority, seize the leadership of the party members and cadres is the key, and put forward higher requirements than the ordinary Party members. Five is to simplify, and
43、strive to achieve concise, easy to understand, easy to remember. The revised is the ruling Party since the first insists on a positive advocate forAll Party members and the self-discipline norms, moral declaration issued to all members of the party and the National Peoples solemn commitment. criteri
44、on of a clean and honest administration consists of 4 parts, 18, more than 3600 words. After the revision of the , a total of eight, 281 words, including lead, specification and Party member cadre clean fingered self-discipline norms, etc. Part 3 members low-cost clean and self-discipline, the main
45、contents can be summarized as four must eight code. Lead part, reiterated on ideal and faith, fundamental purpose, the fine traditions and work style, noble sentiments, such as four must the principle of requirements, strong tone of self-discipline, The higher request for 6 and supervised tenet, the
46、 foothold in permanent Bao the partys advanced nature and purity, to reflect the revised standards requirements. Members of self-discipline norms around the party members how to correctly treat and deal with the public and private, cheap and rot thrifty and extravagance bitter music, put forward the
47、 four norms. Party leader cadre clean fingered self-discipline norms for the leadership of the party members and cadres of the vital few, around the clean politics, from civil servant of the color, the exercise of power, moral integrity, a good family tradition and other aspects of the leadership of the party members and cadres of the four norms norm norm. The Party members self-discipline norms and party members and leadin