《雨污水及箱形沟槽钢板桩支护方案》.doc

太原综保区道路及市政基础设施建设工程深基坑开挖及拉森钢板桩支护专项施工技术方案（备选方案）山西路桥太原武宿综合保税区项目公司2013年3月19日一、工程概况本项目为太原综保区道路及市政基础设施建设工程区内2号路庆云街立交工程施工图设计，下穿通道的起始桩号为K0+595K1+002，全长 407 m，共分39个节段。其中K0+762.539-K0+820.539为暗埋段，长61米，四个节段。通道全宽21.6米。暗埋段采用钢筋混凝土箱涵结构，敞开段采用“U”形槽，南北两侧各长167.5M、178.5M。最大开挖深度为8.9米（暗埋段）。主体结构采用C40钢筋混凝土，抗渗等级W8，箱涵底板下铺20CM厚C20混凝土垫层及基底铺砌100CM厚级配碎石。U形槽结构，侧墙厚0.8米，底板变厚度0.9-0.5米，采用C40钢筋混凝土，抗渗等级W8，箱涵底板下铺20CM厚C20混凝土垫层及基底铺砌100CM后级配碎石，禁边50CM，作为施工工作面。二、地下水及地质情况根据勘察揭露地下水情况与工程地质剖面图综合分析，拟建场地地下水类型为孔隙潜水与微承压水的混合水。主要接受大气降水和侧向补给。勘察期间各勘探点地下水静止水位埋深介于1.3-3.2M之间，静止水位标高介于775.41-775.72M之间。勘察期间属于平水期，丰水期水位可按提高0.50米考虑，枯水期可按降低0.50米考虑。根据勘探揭露地层情况，场地土在勘探深度范围主要由粉质黏土、粉土、砂类土组成，现将各土层描述如下：层，粉土（Q4al+pl）：褐黄色。含云母及氧化铁铝等，表层有煤屑，耕土、植物根。湿，中密。无光泽反应，摇震反应一般，干强度低，韧性低。该层含水量平均值为22.8，天然空隙比平均值0.653，该层标准贯入试验原始锤击数平均值为3.0，修正锤击数平均值为2.9击。该层厚介于35.4米之间，层底埋深介于35.4米之间，层底标高介于771.18773.53之间。层，粉质粘土（Q4al+pl）：褐黄色。含云母及氧化铁铝等。可塑-软塑。稀有光泽，无摇震反应一般，干强度中等，韧性中等。该层天然空隙比平均值0.713，该层液性指数平均值为0.54，该层标准贯入试验原始锤击数平均值为5.2，修正锤击数平均值为4.5击。该层厚介于5.27.7米之间，层底埋深介于9.1010.90米之间，层底标高介于765.83767.75之间。层，粉质粘土（Q4al+pl）：褐黄色。含云母及氧化铁铝等。可塑。稀有光泽，无摇震反应一般，干强度中等，韧性中等。该层天然空隙比平均值0.688，该层液性指数平均值为0.35，该层标准贯入试验原始锤击数平均值为10.3，修正锤击数平均值为7.8击。该层厚介于8.1011.30米之间，层底埋深介于18.021.80米之间，层底标高介于754.85758.78之间。粉质粘土（Q3al+pl）：褐黄色。含云母及氧化铁铝等。可塑。稀有光泽，无摇震反应一般，干强度中等，韧性中等。该层天然空隙比平均值0.585，该层液性指数平均值为0.26，该层标准贯入试验原始锤击数平均值为16.7，修正锤击数平均值为11.7击。该层厚介于4.608.70米之间，层底埋深介于26.4028.50米之间，层底标高介于754.85758.78之间。细砂（Q3al+pl）：褐黄色。含石英、长石、云母等。饱和。颗粒级配较差，磨圆度较差，颗粒含量较小。该层标准贯入试验原始锤击数平均值为23.0，修正锤击数平均值为16.1击。该层未揭穿，揭露厚度介于1.503.60米之间。三、基坑开挖本基坑工程根据设计图纸，采用通道纵向开挖法，分段、分块、分层开挖，开挖以机械为主，人工修挖为辅。（一）开挖施工遵循的原则1、尽可能增加开挖工作面和运输线，采用高挖高弃、低挖低弃的原则。2、在基坑开挖平面内，土方开挖时，分段、分块对称进行，不得超挖。3、开挖前作好截、降排水设施，保证开挖过程中的排水畅通。（二）开挖方案与开挖方法 1、开挖前的准备工作：（1）基坑降水：在基坑开挖前20天进行基坑降水，确保地下水水位控制在开挖面以下1m；地下水的降排应贯穿整个基坑开挖及结构施作施工全过程。（2）拉森钢板桩支护：在距暗通道中心线12.3m两侧设拉森钢板桩支护。 2、基坑开挖施工基坑属于对称的长条形基坑，全长 407 m，共分39个节段，其最大开挖深度为8.9米,该段落基坑开挖采用“通道纵挖法”。整个基坑施工严格按照设计要求从通道中心K0+793.039处开始向两侧分段上下台阶一次开挖成型。上台阶1-4m范围内土方开挖完毕后，留一工作平台，挖掘机在工作平台上开挖下台阶4-8.9m范围内土方，土方堆放于上台阶，由另一挖掘机将堆放于上台阶的土方装车拉运走，直至开挖到坑底垫层顶面标高。按照此方法分段、分块开挖敞开段及深埋段基坑。当挖至坑底垫层顶面标高时，复核中线、标高准确无误后，人工进行修整，严禁超挖回填虚土，至设计标高后，进行100cm厚碎石垫层及混凝土底板的施工。每段开挖中又必须按照分段、分块，并限时完成每段的开挖和支撑。四、 支护设计 由于本工程施工场地土质疏松，地下水位高，开挖深度达到8.9米，根据以往该区域的施工经验，基坑开挖前需要进行支护。根据本工程施工特点，综合工程造价和工期各方面考虑，我单位拟采用拉森钢板桩进行支护兼作止水帷幕。拉森钢板桩工艺能通过钢板桩两侧自身锁扣互相紧密的咬合在一起而形成一道密封性非常好的桩墙，整体性非常好，从而提高了钢板桩的支护强度和止水能力，另外就是钢板桩施工工艺简单，施工速度非常快，并且没有龄期限制，打完钢板桩后就能马上开挖，基坑回填后可以将拉森钢板桩拔出进行重复利用，能降低工程造价。1、本次使用的拉森钢板桩规格有两种：对于深度4H6m的基坑（K0+635-K0+685、K0+880-K0+935共计105米）采用管井降水，冷弯LWBU14B-9m拉森钢板桩支护；对于深度8.9mH6m的基坑（K0+685- K0+880共计195米）采用管井降水，冷弯LWBU12A-12m拉森钢板桩支护。2、箱形通道支护按条形围护考虑，先卸载至-2.0m，再采用四周连续布置钢围檩，并用锚索拉结。钢围檩采用HW400×400型钢。五、 施工组织机构项目经理施工负责人 技术负责人安全负责人质量负责人测 量组材料供应组起重吊装组设备操作组焊接组电工组维修组 六、 现场施工作业条件1、拉森钢板桩施工采用的振动桩锤需要200KW电源，现场负责提供电源，考虑到本次施工线路比较长，应考虑在现场备用1台移动柴油发电机。2、打桩前，应对打桩场地下面埋设情况进行详细调查确认，以防打桩期间破坏地下重要管网设施，同时还要确认打桩场地下面是否有障碍物，如果有障碍物应开挖清除掉，以满足打桩作业条件。3、拉森钢板桩施工需要配备一台50吨坦克吊，坦克吊行走区域必须平整，必要时应用挖机或装载机平整场地。4、打桩前，应由测量人员在现场准确放出打桩位置边线。七、 施工流程施工准备-施工机具和人员进场-打桩场地障碍物清理整平-打桩位置放线-钢板桩施工（箱形通道需先卸载至-2.0m后再施打钢板桩）-设置围檩和锚索系统-基坑开挖-结构施工-台背回填-拆除锚索系统-拔出拉森钢板桩八、 主要施工方法拉森钢板桩施打拉森钢板桩施打采用振动单独打入法，该方法需要一台50吨坦克吊和一台振动桩锤。打桩过程中要控制好打桩顺序和打桩垂直度，发现垂直度偏差过大应及时调整，为保证转角部位的止水效果，遇到转角部位应多打34根钢板桩。拉森钢板桩拔出结构主体施工完回填后，要考虑拔出拉森钢板桩，以便重复利用。i,pc Opinions and suggestions on the party's mass line educational practiceAccording to the central and provincial, municipal unified deployment, according to municipal Party committee "about carrying out the party's mass line educational practice activity in the city's implementation opinions, the spirit of the party's mass line educational practice activities from 20* in January to 99 months, carried out at all levels of departments and directly affiliated institutions and grass-roots party organizations. According to my actual County, the county to carry out the education practice put forward the following implementation opinions.First, the overall requirementsCounty county education practice to the eighteen Party of eight, the spirit of the the third Plenary Session of the 18th CPC Central Committee as the guidance, conscientiously implement the spirit of general secretary Xi Jinping book series of important speech, earnestly implement the Central Committee really, opinions and advice > < < >, < party implementing the guiding ideology of opinions to determine the objectives and requirements, step method, in accordance with the "" look in the mirror, dress up, wash bath, cure treatment, the general requirements of "for the people pragmatic honest people as the theme, in carrying forward the spirit of Zhuanglang Zhuang, improve their work style, service to the masses of the people, the foundation of consolidating grassroots, promote transformation across efforts, to further implement the central eight regulations and < The opposition party and government austerity waste regulations "," double section "provincial regulations, municipal provisions of the" twelve "plan and the implementation measures for < on improving the work style of close ties with the masses law, highlight style building, carry out the whole wind spirit, resolutely oppose formalism, bureaucracy, hedonism and wasteful extravagance to solve the problems, Party members and cadres of the style and the masses of people strong, the Ministry of Party members and cadres to further improve their thinking and understanding, to further change the style of the wind, the masses to close, honest and pragmatic people honest image to further establish the foundation to further reinforce the basic level. Style of the building of the new results to promote the construction of a powerful force of the county and the ecological culture of the county and county construction.In educational practice activities of the unit is mainly: the county and below county departments under the organs, enterprises and institutions directly under the township, street, and community, village, non-public economic organizations, social organizations and other grass-roots organizations. Agencies and branches, each single unit, follow the rules on internal institutions. Educational practice with step by step.To adhere to the county leadership, leadership and leading cadres to focus on outstanding catch to directly contact the service of the masses of law supervision departments and window units, service industry, educational practice, pay attention to grasp the heavy towns, streets and villages, community education activities and the masses of grassroots groups in close contact to strengthen, and the majority of Party members, cadres and the mass line line Marx doctrine view of the masses and the party's education.Always speak seriously as a basic attitude, adhere to positive education, to carry out criticism and self criticism group, adhere to the pragmatic, more emphasis on leadership, pay more attention to the layers of the demonstration, more focus on the four winds, solve the problem, pay more attention to open the door, the participation of the masses, pay more attention to the classification guidance. Orderly, pay more attention to the cooperation and cohesion driven, more strict requirements on injection, really supervision practice, ensure education practice is not empty is not empty is not partial, not as a mere formality.Two, the key point of the taskThe main task of the county's education practice is to seize against "four wind" this focus on centralized solve outstanding problems asked County, township leadership and leading cadres of the four winds, the disadvantages of the style, scale behavior to a large scale investigation, overhaul, cleaning greatly. At the same time, respond to the concerns of the masses, safeguard the interests of the masses, pay attention to solve practical problems, solve the people around the unwholesome tendencies especially on eat, take the card, Yong lazy luxury, extravagance and waste fees, privileges and other issues, timely and effective, without any discount to solve, to improve the style of real implementation of the requirements of real to the grassroots, real let group Benefit the public.(a) focus on solving the "four winds" outstanding issuesThe central and provincial requirements, the county leadership and leading cadres of key performance concept is not correct, do not dare to play, to engage in "image project", "political project", a leadership guide, a set of ideas, orders and prohibitions, and a policy, there are countermeasures county. The units directly under the heavy focus on solving Yung lazy drag, buck passing skin, work is not implemented, the service is not active. The dynamic problem of law enforcement and supervision departments and window units, service industry mainly solve the door hard, ugly face, something difficult, and arbitrary charges, fines, levies, and breach of privilege, chinakayao, not the problem of law. The township, street The collar of leading bodies and leading cadres to solve key does nottheir own conditions to develop the correct road, the maximum to avoid investment risk, gain profit.(three) vigorously promote the brand. To establish brand awareness, awareness of the use of brand, brand value, brand acquisition performance, enhance the competitive strength. Concentrated manpower, careful planning, packaging and publicity of a number of unique, market influence and coverage of the brand, the implementation of key breakthroughs, to enhance the competitive strength, walking business road the competition of alienation and characteristics, the pursuit of stability and development of the market.(four) to promote the integration of resources. To further broaden their horizons, effective integration of resources within the group, the city resources, other industries and regional resources, mutual trust, mutual benefit, seeking win-win principle, in the framework of national policies and regulations, strict inspection and argumentation, legal consultation, examination and approval procedures, strict regulation of economic activities, attract injection the social investment to the industry group, to achieve leveraging the development, ensure that the value of state-owned assets.(five) to strengthen the construction management personnel. Strengthen the management of education and training of cadres and workers of the existing business, firmly establish the concept of the market, enhance the sense of crisis to adapt to market competition, the sense of urgency, improve the ability to respond to market competition, improve management and operation of the market. At the same time, according to the need of industrial development, vigorously the introduction of high-quality management management personnel, and strive to build a high-quality professional management team, hard work, and promote the entire workforce knowledge structure, age structure, structure optimization and upgrading ability, enhance core competitiveness, adapt to the need of market competition.(six) seriously study the policy for policy. Serious research about social support the development of cultural undertakings in the country and the XX policy, especially the policy of industrial development, financial investment policy, financial policy and tax policy, and actively seek policy, projects and funds, enterprise and industry group mission to promote leapfrog development.拔桩也是采用振动锤，利用振动锤产生的强迫振动，扰动土质，破坏拉森桩周围土体的粘聚力以克服拔桩阻力，依靠附加起吊力的作用将桩拔出。先用桩锤夹钳夹住桩顶头部振动12min，使桩周围的土体松动产生“液化” ，减少土体对桩的摩阻力，然后慢慢的往上振拔。拔桩时注意桩机的负荷情况，发现上拔困难或拔不上来时，应停止拔桩，先振动12min后再往下锤0.51.0m再往上振拔，如此反复可将桩拔出来。围檩和支撑安装围檩安装固定，首先在安装位置下方焊接承受围檩自重的短型钢牛腿托架，然后将围檩与钢板桩紧靠焊接固定，牛腿设置间距为5.0米，牛腿材料尽量采用废边角料I20工字钢，呈三角形，长度500mm。需要强调的是，对于部分拉森钢板桩内侧面与围檩之间存在的空隙，必须用不同厚度的钢楔子和钢板将空隙塞紧并焊接牢固使围檩受力均匀。围檩安装固定完毕，应根据现场实际尺寸，进行锚索的施工，见附图。围檩和锚索施工应与开挖工序和结构施工密切配合，提前对方案进行确认，避免影响后序工作。基坑管井降水由于该场地地下水位比较高，为便于基坑开挖，需要提前打井降水。降水井采用无砂管管井，均布置在沟槽里面，井距10.0米，井深15.0米，打井成孔直径600mm，无砂管规格采用外径400×壁厚50。基坑开挖期间应安排专人看护好降水井，防止被挖掉或掩埋。九、安全技术措施1、作业人员进入现场必须戴好安全帽等劳保用品，作业前应对作业环境和周边环境进行确认，增强自我保护意识，做到“三不伤害”。2、打拉森桩作业之前，应对打桩区域下面埋设情况进行确认，防止打桩过程中遇到不明地下设施和破坏重要管线。3、在吊装作业期间，安排专业起重工负责指挥吊装，吊装作业前，应负责检查吊装钢丝绳的完好性能，防止在吊装作业时发生钢丝绳破损断裂的现象。4、吊装期间，吊装作业半径范围内不得有人，尤其是在钢板桩吊装过程中，钢板桩上面不得站人，下面不得有人。十、应急措施1、打桩期间如果遇到地下障碍物无法穿透，应用挖机或液压锤清除。2、打桩期间应严格控制打桩垂直度，保证每根桩之间互相咬合好，同时在基坑转角部位多打34根钢板桩，延长转角部位的渗水路线，基坑挖开后，如果发现桩身有渗漏水现象，应采取塞棉布和焊接钢板的方法进行堵漏。3、打钢板桩和基坑开挖期间，应对场地周围地面和桩顶做好变形监测工作，一旦发现变形过大、过快、超过报警值或者其它异常情况，应立即停止施工，并采取必要的加固措施。