斜孔灌浆技术在上沟水利枢纽工程坝基帷幕灌浆中的应用研究
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摘要
水工建筑物,尤其是坝基工程,其渗漏和渗透压力是影响工程运行和安全的重要因素。在水利水电工程建设中,灌浆与地下排水是解决水文地质问题和基础设计、施工的关键技术措施,受到极大关注。
现行的国内外水工建筑物水泥灌浆施工技术规范对灌浆做了传统意义上的一般规定,实践中仍有很多需要解决的问题。那种不论岩体裂隙面陡缓及其发育状况,几乎都是把钻孔布置成与岩体天然地面或开挖面呈垂直方向,不去管这样的钻孔会不会遇到裂隙或遇到多少条裂隙,在这些前提下开展的任何灌浆工作都没有真正与被处理岩体的水文地质、工程地质条件很好结合起来,是造成灌浆效果不理想、浪费投资、增加修复工程量等主要原因。
鉴于此,上沟灌浆工程中引用了马国彦教授建议的新方法,对该理论方法的可行性、先进性进行检验,以便更好为我省灌浆工作服务。
要想对一个事物有所了解,必须先从它的特征开始,因此,论文首先对工程区地质条件进行了全面分析、研究,通过分析得出工程区可以作为一个均值区来考虑,岩体结构面倾角以陡倾角为主,表层岩体透水严重,必须进行灌浆处理,岩体结构面具有的特征可以采用新的灌浆方法。
① 区域构造背景分析中,坝址区几个主要断层受敦化-密山断裂影响为主,同时受到山字型构造影响,它们发育总体特征上较为均一;坝址区裂隙发育情况受这些断层控制,它们发育特征也应有一致性,大量研究资料表明在相同或相似地质构造背景中,在相似岩性和相似组合关
系的岩组内,岩体结构面特征是相似的,可以作为同一个均值区来考虑;
② 通过地形地貌及岩体物理力学特性分析,把工程区岩体进行分类细化,对岩体风化、卸荷特征进行分析,把岩体结构面按性质归类;
③ 对岩体水文地质条件分析后,了解到坝基灌浆是必要的,而且是可灌性岩体,根据岩性、构造和透水性,把坝址区岩体分为四类,本次主要研究I区的I2区;
④ 为了进行后续工作,对采集到的岩体结构面参数按一些方法进行统计、聚类分析,得出研究区岩体结构发育总体特征。
经过上述对灌浆介质(岩体)比较详细研究,然后应用GJMZ程序开始最优灌浆钻孔方位设计工作,该软件有两个假设条件:①在相对均质区内,每条裂隙的产状在每一级斜孔深度范围内是相同的;②在相对均质区内,用一组铅直孔或用一组产状相同的斜孔(不能与裂隙产状相同),都可钻穿各组裂隙。
设计中先把不同的裂隙分组,分别计算每一组裂隙的效益系数,然后根据各组结构面发育情况,求出简化处理后总的效益系数。例如,对于节理宽度,为简化计算,把宽度转化到条数上,即假设统计的平均隙宽为0.4mm,对于某条节理裂隙宽度为1.2mm时,相当于有三条这样的节理,重复三次输入该节理产状,对其它特征也采用类似方法处理,实际程序计算时以此来作为控制变量,根据需要采用。
通过计算分析,在相同的斜孔方位下,随着斜孔倾角的增大,斜孔效益系数有减少的趋势。结合施工难度、效益分析,决定采用倾角50度的灌浆斜孔,既能保证质量,又能提高40%的效益。斜孔方位倾向于NE。
灌浆孔距一般来说根据工程、水文地质资料,特别是浆液运移途径等资料进行估算,提出初步数据,最后通过灌浆试验确定。本次利用GJMZ程序通过计算浆液扩散半径来初步选定孔距,确定为3.5、4.2m两种。实际操作中按初步定下孔距采用对分法逐级加密进行,确定最终合理经济孔距。
为了验证、评定该方法确定灌浆孔参数实践中可行性、合理性,进行了现场灌浆试验,试验在防渗帷幕线上进行,桩号为0+077-0+107.8m,孔序分为I、II、III序。采用的钻孔方位为倾向NE47010'48'',倾角500,孔距3.5m、4.2m,开孔孔径φ91mm,基岩钻进孔径φ75、φ59mm,灌浆基岩接触段长度3m,其余各段按常规5m,灌浆压力采用0.4-1.0MPa,孔底基岩段采用1-3MPa,灌浆材料采用室内试验配制的稳定浆液。试验过程严格按规范规定执行。
试验后对灌浆质量、效果采用直观检验、钻孔电视揭露结石分布情况、声波法测定灌浆前后波速变化、压水试验等方法进行检验。对灌浆过程采集到各种数据、信息(如注灰量、岩体透水性等)进行加工、分析,并参考省内、国内已有相关资料,把该方法与常规方法得到的各种数据进行对比分析,最后,得出结论认为试验达到了预期目的,该新方法在实践中是可行的,值得结合实际情况推广使用。
同时,论文指出该方法应用中的不足之处,并提出了进一步研究的设想。
Seepage and infiltration force are key factors in safely exercise to water conservancy works, especially for dam ground. And that, grouting and ground water drainage is key technique in solving problems of hydrogeology and foundation design, and being paid close attention to.
At present, the using construction specification of cement grouting used for hydraulic structures has only a general rule in traditional meaning on grouting, there are many problems in practice need to be solved. Arranging grouting holes that are vertical to ground and excavation face, regardless if it will drill through how many fractures, etc. All this that disconnecting hydrogeology and engineering geology of treated rock to project practice are main reasons in wasting money, increasing works of maintenance and bringing bad grouting effect.
In view of the above mentioned situations, in order to make better work to our province grouting works, we apply Professor Ma’s new methods to Shanggou project, and examine it’s advanced and feasible in practice.
To know a matter, we must know it from it’s features, so, at first, this paper made a analyzing and researching engineering
geology and hydrogeology on dam area. Through analyzing, we can know that the project area may be treated as homogeneous, structure faces of rock are mainly steep inclination, rock need to be grouted, new technique may be used, and so on.
① From tectonic background of district, main faults in project area are effected by Dunhua-Mishan rupture and Shanzhixing structure, and their developing characteristics should be approximately consentaneous, meanwhile, the joints effected by faults also should have equality features. Therefore, the features of structure faces in study area may be treated as homogeneous;
② According to landforms and physics and mechanics feature, making a more sorting of rock, and sorting the nature of structure by analyzing weathering and relaxation feature of rock;
③ After knowing the hydrogeology character of rock, the curtain grouting was needed and the rock was penetrability, at the same time, the rock was divided into 4 kinds, the research work was main in Area I2;
④ Finally, answering the general characters of rock through some calculation methods.
After all mentioned works were be done, we designed using GJMZ program optimum orientation and inclination angle of grouting holes, the two hypothesis condition of GJMZ : first, in relatively homogeneous, the occurrence of every joint at every incline hole depth is same; second, a group of vertical holes and
incline holes all may drill through all the joints but their occurrence should be different.
In design, first, sorting different group joints occurrence, and calculating inclined hole benefit coefficient for every group joints, then calculating total benefit coefficient by simplified treatment. For example, to the width of joints, we treated it as numbers according to calculated average width, to other features of joints, the probably method was applied, in program these features of structure faces were treated as controlling condition.
The benefit coefficient is more smaller as the more larger dip angle under same orientation of inclined hole, at last, the dip angle degree 50 and orientation NE of inclined hole were decided by compositive analysis.
The distances between holes were confirmed as 3.5、4.2m through GJMZ program in this test. In order to verify these parameters of grouting hole and the feasibility of mentioned method, a test in field was donned, the test circumstances is:① the position is on curtain axes, the stake number is 0+077 to 0+107.8m; ② the order is I、II、III; ③ the orientation is NE47010'48'' and dip angle is degree 50 ④ the distance between hole is 3.5、4.2m ⑤ the length of grouting section is 3、5m and the press is 0.4 to 1.0 MPa, ⑥ the grouting material is stable grouting fluid compounded in lab. The entire course is under correlative specification and code strictly.
After test, we used some methods, such as nak
现行的国内外水工建筑物水泥灌浆施工技术规范对灌浆做了传统意义上的一般规定,实践中仍有很多需要解决的问题。那种不论岩体裂隙面陡缓及其发育状况,几乎都是把钻孔布置成与岩体天然地面或开挖面呈垂直方向,不去管这样的钻孔会不会遇到裂隙或遇到多少条裂隙,在这些前提下开展的任何灌浆工作都没有真正与被处理岩体的水文地质、工程地质条件很好结合起来,是造成灌浆效果不理想、浪费投资、增加修复工程量等主要原因。
鉴于此,上沟灌浆工程中引用了马国彦教授建议的新方法,对该理论方法的可行性、先进性进行检验,以便更好为我省灌浆工作服务。
要想对一个事物有所了解,必须先从它的特征开始,因此,论文首先对工程区地质条件进行了全面分析、研究,通过分析得出工程区可以作为一个均值区来考虑,岩体结构面倾角以陡倾角为主,表层岩体透水严重,必须进行灌浆处理,岩体结构面具有的特征可以采用新的灌浆方法。
① 区域构造背景分析中,坝址区几个主要断层受敦化-密山断裂影响为主,同时受到山字型构造影响,它们发育总体特征上较为均一;坝址区裂隙发育情况受这些断层控制,它们发育特征也应有一致性,大量研究资料表明在相同或相似地质构造背景中,在相似岩性和相似组合关
系的岩组内,岩体结构面特征是相似的,可以作为同一个均值区来考虑;
② 通过地形地貌及岩体物理力学特性分析,把工程区岩体进行分类细化,对岩体风化、卸荷特征进行分析,把岩体结构面按性质归类;
③ 对岩体水文地质条件分析后,了解到坝基灌浆是必要的,而且是可灌性岩体,根据岩性、构造和透水性,把坝址区岩体分为四类,本次主要研究I区的I2区;
④ 为了进行后续工作,对采集到的岩体结构面参数按一些方法进行统计、聚类分析,得出研究区岩体结构发育总体特征。
经过上述对灌浆介质(岩体)比较详细研究,然后应用GJMZ程序开始最优灌浆钻孔方位设计工作,该软件有两个假设条件:①在相对均质区内,每条裂隙的产状在每一级斜孔深度范围内是相同的;②在相对均质区内,用一组铅直孔或用一组产状相同的斜孔(不能与裂隙产状相同),都可钻穿各组裂隙。
设计中先把不同的裂隙分组,分别计算每一组裂隙的效益系数,然后根据各组结构面发育情况,求出简化处理后总的效益系数。例如,对于节理宽度,为简化计算,把宽度转化到条数上,即假设统计的平均隙宽为0.4mm,对于某条节理裂隙宽度为1.2mm时,相当于有三条这样的节理,重复三次输入该节理产状,对其它特征也采用类似方法处理,实际程序计算时以此来作为控制变量,根据需要采用。
通过计算分析,在相同的斜孔方位下,随着斜孔倾角的增大,斜孔效益系数有减少的趋势。结合施工难度、效益分析,决定采用倾角50度的灌浆斜孔,既能保证质量,又能提高40%的效益。斜孔方位倾向于NE。
灌浆孔距一般来说根据工程、水文地质资料,特别是浆液运移途径等资料进行估算,提出初步数据,最后通过灌浆试验确定。本次利用GJMZ程序通过计算浆液扩散半径来初步选定孔距,确定为3.5、4.2m两种。实际操作中按初步定下孔距采用对分法逐级加密进行,确定最终合理经济孔距。
为了验证、评定该方法确定灌浆孔参数实践中可行性、合理性,进行了现场灌浆试验,试验在防渗帷幕线上进行,桩号为0+077-0+107.8m,孔序分为I、II、III序。采用的钻孔方位为倾向NE47010'48'',倾角500,孔距3.5m、4.2m,开孔孔径φ91mm,基岩钻进孔径φ75、φ59mm,灌浆基岩接触段长度3m,其余各段按常规5m,灌浆压力采用0.4-1.0MPa,孔底基岩段采用1-3MPa,灌浆材料采用室内试验配制的稳定浆液。试验过程严格按规范规定执行。
试验后对灌浆质量、效果采用直观检验、钻孔电视揭露结石分布情况、声波法测定灌浆前后波速变化、压水试验等方法进行检验。对灌浆过程采集到各种数据、信息(如注灰量、岩体透水性等)进行加工、分析,并参考省内、国内已有相关资料,把该方法与常规方法得到的各种数据进行对比分析,最后,得出结论认为试验达到了预期目的,该新方法在实践中是可行的,值得结合实际情况推广使用。
同时,论文指出该方法应用中的不足之处,并提出了进一步研究的设想。
Seepage and infiltration force are key factors in safely exercise to water conservancy works, especially for dam ground. And that, grouting and ground water drainage is key technique in solving problems of hydrogeology and foundation design, and being paid close attention to.
At present, the using construction specification of cement grouting used for hydraulic structures has only a general rule in traditional meaning on grouting, there are many problems in practice need to be solved. Arranging grouting holes that are vertical to ground and excavation face, regardless if it will drill through how many fractures, etc. All this that disconnecting hydrogeology and engineering geology of treated rock to project practice are main reasons in wasting money, increasing works of maintenance and bringing bad grouting effect.
In view of the above mentioned situations, in order to make better work to our province grouting works, we apply Professor Ma’s new methods to Shanggou project, and examine it’s advanced and feasible in practice.
To know a matter, we must know it from it’s features, so, at first, this paper made a analyzing and researching engineering
geology and hydrogeology on dam area. Through analyzing, we can know that the project area may be treated as homogeneous, structure faces of rock are mainly steep inclination, rock need to be grouted, new technique may be used, and so on.
① From tectonic background of district, main faults in project area are effected by Dunhua-Mishan rupture and Shanzhixing structure, and their developing characteristics should be approximately consentaneous, meanwhile, the joints effected by faults also should have equality features. Therefore, the features of structure faces in study area may be treated as homogeneous;
② According to landforms and physics and mechanics feature, making a more sorting of rock, and sorting the nature of structure by analyzing weathering and relaxation feature of rock;
③ After knowing the hydrogeology character of rock, the curtain grouting was needed and the rock was penetrability, at the same time, the rock was divided into 4 kinds, the research work was main in Area I2;
④ Finally, answering the general characters of rock through some calculation methods.
After all mentioned works were be done, we designed using GJMZ program optimum orientation and inclination angle of grouting holes, the two hypothesis condition of GJMZ : first, in relatively homogeneous, the occurrence of every joint at every incline hole depth is same; second, a group of vertical holes and
incline holes all may drill through all the joints but their occurrence should be different.
In design, first, sorting different group joints occurrence, and calculating inclined hole benefit coefficient for every group joints, then calculating total benefit coefficient by simplified treatment. For example, to the width of joints, we treated it as numbers according to calculated average width, to other features of joints, the probably method was applied, in program these features of structure faces were treated as controlling condition.
The benefit coefficient is more smaller as the more larger dip angle under same orientation of inclined hole, at last, the dip angle degree 50 and orientation NE of inclined hole were decided by compositive analysis.
The distances between holes were confirmed as 3.5、4.2m through GJMZ program in this test. In order to verify these parameters of grouting hole and the feasibility of mentioned method, a test in field was donned, the test circumstances is:① the position is on curtain axes, the stake number is 0+077 to 0+107.8m; ② the order is I、II、III; ③ the orientation is NE47010'48'' and dip angle is degree 50 ④ the distance between hole is 3.5、4.2m ⑤ the length of grouting section is 3、5m and the press is 0.4 to 1.0 MPa, ⑥ the grouting material is stable grouting fluid compounded in lab. The entire course is under correlative specification and code strictly.
After test, we used some methods, such as nak
引文
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2. 《上沟水利枢纽工程初设报告》,吉林省水利设计院,1999,1-2,10-20.
3. 熊进,祝红,董建军,长江三峡工程灌浆技术研究[M] .北京:中国水利水电出版社,2003.7,1-10.
4. 《中华人民共和国行业标准.SL62-49水工建筑物水泥灌浆施工技术规范》.北京:中国水利水电出版社,1994.
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