1、精選優(yōu)質(zhì)文檔-傾情為你奉上淺析公路路基邊坡防護(hù)摘要：本文通過分析公路路基邊坡的破壞形式及原因，分析了路基邊坡防護(hù)設(shè)計(jì)原則，詳細(xì)介紹了公路邊坡的防護(hù)方法，以保證路基的穩(wěn)定和防治各種路基病害，確保公路的正常使用品質(zhì)及投資效益。 關(guān)鍵詞： 路基防護(hù)是保證路基強(qiáng)度和穩(wěn)定性的重要措施之一,防護(hù)的重點(diǎn)是路基邊坡,由于地形的變化,適路設(shè)計(jì)標(biāo)高與天然地面標(biāo)高的相互關(guān)系不同,會出現(xiàn)高于天然地面的填方路基即路堤、低于天然地面的挖方路基即路塹和介于前兩者之間的半填半挖路基。由巖土體填挖而成的路基,改變了原地層的天然平衡狀態(tài),且暴露于環(huán)境中,長期受各種自然因素的影響,巖土體的物理力學(xué)性質(zhì)會發(fā)生較大的變化,引起巖土體變

2、形、移動,破壞邊坡的穩(wěn)定,甚至導(dǎo)致一系列環(huán)境地質(zhì)問題和生態(tài)環(huán)境問題,如崩塌滑坡、泥石流、土壤侵蝕和植被破壞等。因此為保證路基的穩(wěn)定和防治各種路基病害,除做好路基排水工作外,還需結(jié)合當(dāng)?shù)厮摹⒌刭|(zhì)及材料等情況,采取有效措施,對各類土、石邊坡進(jìn)行必要的防護(hù)。 一、邊坡破壞形式及原因 路基邊坡的滑塌是最常見的路基病害之一,根據(jù)邊坡土質(zhì)類別、破壞原因和規(guī)模不同,主要破壞形式為溜方、滑坡、剝落和碎落崩塌四種。溜方是由于少量土體沿土質(zhì)邊坡向下移動所形成,即邊坡上薄的表層土下溜,通常是由于降水、降雨等流動水沖刷邊坡或施工不當(dāng)而引起的?；率侵敢徊糠滞馏w在重力作用下沿邊坡的某一滑動面滑動,

3、主要是因土體的穩(wěn)定性不足引起的。路堤邊坡發(fā)生滑坡的主要原因是邊坡坡度過陡或坡腳被挖空,或填土層次安排不合適等;路塹邊坡發(fā)生滑坡的主要原因是邊坡高度和坡度與天然巖土層次的性質(zhì)不相適應(yīng)。剝落和碎落是指邊坡風(fēng)化巖層表面,在各種外界環(huán)境的影響下使表層巖石從坡而上剝落下來的破壞形式。崩塌通常是指較大的石塊脫離邊坡表面沿坡而滾落下來。 二、路基邊坡防護(hù)設(shè)計(jì)原則 公路邊坡沿公路分布的范圍廣,對自然環(huán)境的破壞范圍大,如果在防護(hù)的同時(shí),能夠注意保護(hù)環(huán)境和創(chuàng)造環(huán)境,采用適當(dāng)?shù)木G化防護(hù)方法來進(jìn)行,則會使公路具有安全、舒適、美觀、與環(huán)境相協(xié)調(diào)等特點(diǎn),也將會產(chǎn)生可觀的效益、社會效益和生態(tài)效益。因此,

4、邊坡設(shè)計(jì)應(yīng)遵循“安全綠色、水土保持、恢復(fù)自然、環(huán)保之路”的設(shè)計(jì)原則。 三、路基邊坡防護(hù)方法 1.植草防護(hù)。植物防護(hù)則是在邊坡上種植草或植樹,以減緩邊坡上的水流速度,利用植物根系固結(jié)邊坡表層土壤以減輕沖刷,從而達(dá)到保護(hù)邊坡的作用。植物防護(hù)不僅可以美化公路環(huán)境,調(diào)節(jié)邊坡的濕溫,起到固結(jié)和穩(wěn)定邊坡的作用,而且又比較簡單、經(jīng)濟(jì)。 植草防護(hù)應(yīng)選擇根系發(fā)達(dá)、莖矮葉茂耐旱草種,嚴(yán)禁采用生長在泥沼地的草皮。直接植草護(hù)坡方法如下:其一,在土質(zhì)坡面上用草籽、肥料、水拌和,直接噴灑在坡面上,優(yōu)點(diǎn)是方法簡單、施工方便、成本較低,但易受風(fēng)雨的侵蝕;其二,在修整好的坡面上,將粘土、種子、肥料

5、、水等混合物用噴漿機(jī)直接噴射于坡面,與原土壤粘合,種子發(fā)芽后便會植根于邊坡土壤中,形成整體保護(hù)。上述兩種方法在植草初期,應(yīng)免受風(fēng)雨的侵蝕,可覆蓋纖維網(wǎng),由于坡面沒有任何的加筋處理,在暴雨和徑流的沖蝕下極易導(dǎo)致坡面破壞,因此一般應(yīng)在每年3-5月進(jìn)行。 2.工程防護(hù)。工程防護(hù)主要是針對不適宜植物生長的土質(zhì)填、挖方邊坡或風(fēng)化嚴(yán)重、節(jié)理發(fā)育不良的巖石路基邊坡等,采取工程防護(hù)措施即設(shè)置人工構(gòu)造物防護(hù)。3.干砌片石。干砌片石適用于保護(hù)邊坡免受大氣降水和地面徑流的侵害,以及保護(hù)浸水路堤邊坡免受水流沖刷。對嚴(yán)重潮濕或有凍害的路段、長期承受主動土壓力地段一般不宜采用干砌片石防護(hù),可用于下邊坡中的土質(zhì)邊

6、坡防護(hù),坡度為1:1.5-1:2。 4.漿砌片石。漿砌片石設(shè)置在浸水路堤及可能發(fā)生坡面被沖刷的土質(zhì)邊坡,應(yīng)做好排水與防護(hù)的結(jié)合,否則不宜采用。當(dāng)水流速度較大時(shí)(如4-5m/s),波浪作用較強(qiáng),以及河流可能有流木及其他撞擊物等沖擊作用時(shí),宜采用漿砌片石防護(hù),必要時(shí)可與浸水擋墻或護(hù)面墻同時(shí)設(shè)置。漿砌片石護(hù)坡優(yōu)點(diǎn)是耐久性較好,適宜防護(hù)不同控制邊坡中的巖土層和不同位置的邊坡,且造價(jià)適中,故適用于上下邊坡中的一般坡面。 5.拱式、網(wǎng)格防護(hù)。這種防護(hù)方式克服了魚鱗狀砌石防護(hù)排水抗沖刷能力弱和污工量大的特點(diǎn),最大限度地綠化坡面,外觀較好,在高填方、長直線的護(hù)坡段,能達(dá)到美化、綠化的雙重效

7、果,是近年來公路防護(hù)常用的方法之一。缺點(diǎn)是施上較繁瑣,勞動強(qiáng)度大,對坡面要求嚴(yán)格,拱內(nèi)必須填土植草或進(jìn)行其他工程防護(hù),否則易被雨水沖蝕。 6.預(yù)制塊鋪砌防護(hù)。這是目前高速公路上應(yīng)用較多的護(hù)坡方法之一,由于預(yù)制塊的規(guī)格一致,易于施工,外觀整齊,最大限度地減少了坡面防護(hù)對植草綠化的依賴性,即使坡面綠化效果不好,也不容易造成太嚴(yán)重的沖刷現(xiàn)象,所以,目前大多數(shù)高速公路采用這種方式,缺點(diǎn)是造價(jià)高,施工難度大。 7.噴射混凝土防護(hù)。噴射混凝土法分為素噴法和錨噴法。素噴法為直接將高標(biāo)號砂漿噴射在大致平整的巖面上,使坡面易松散的顆粒得以穩(wěn)固,保證行車及行人的安全。它用于表層易松散的風(fēng)化巖面

8、。錨噴法,其工作原理是利用錨桿將滑動體固定在山體上,以錨桿約束山體的滑動,并在滑動體表面錨頭上加掛鋼筋網(wǎng)并噴射混凝土,在滑動體表面形成鋼筋混凝土板體結(jié)構(gòu),這樣可以將松散的巖石固定為一個(gè)整體,以達(dá)到徹底根治滑坡的目的。錨噴法適用于大部分巖石土和碎石土等地質(zhì)結(jié)構(gòu)山體和易產(chǎn)生滑坡地段,它可預(yù)防早期滑坡的產(chǎn)生。只要產(chǎn)生滑動的區(qū)域面積不很大,滑動層不很厚,都可以采用此方法。 此外,對于邊坡破壞較嚴(yán)重的情況,如出現(xiàn)塌方、滑坡以及可能出現(xiàn)失穩(wěn)等,必須采取相應(yīng)的措施來確保邊坡的穩(wěn)定性(強(qiáng)度方面)和安全性(變形方面)。根據(jù)邊坡的不良工程地質(zhì)特征和滑坡加固治理與防護(hù)工程特點(diǎn),主要選取適用性強(qiáng)、易于操作、

9、工程負(fù)效應(yīng)小的措施,如抗滑樁、錨桿(索)、擋土墻、削坡和灌漿等,使其分別適用于不同塌方、滑坡的物理力學(xué)條件和地質(zhì)條件。 123According to the highway subgrade slope protectionabstract this article through the analysis of road foundation slope failure forms and reasons, analyzes the roadbed slope protection design principles, detailed introduces the highwa

10、y slope protection method, in order to guarantee the stability of roadbed and prevention and control of all kinds of roadbed disease, to ensure the normal use of the highway quality and benefit of investmentkey words highway subgrade slope protectionRoadbed protection is to guarantee the stability o

11、f roadbed strength and one of the important measures, protection is the focus of the embankment slope, the change of the terrain, ShiLu design elevation and natural ground conductivity of the relationship between different, there will be higher than that of the natural ground embankment fill subgrad

12、e construction of the ground below natural excavated one that cut and between the two and a half between fill subgrade in geotechnical engineering by half to dig into roadbed fill dug, change the original layer of the natural balance, and exposed to a natural environment, long-term affected by vario

13、us natural factors, the physical and mechanical properties of rock mass will been great changes, cause rock mass deformation mobile, destroy the stability of the slope, and even cause a series of geological environment problems and the ecological environment problems, such as collapse landslides of

14、soil erosion and damage to vegetation, etc .So to ensure the stability of roadbed and prevention and control of all kinds of roadbed disease, in addition to the drainage roadbed, still need to be combined with the local hydrological geology and material of case, take effective measures to all kinds

15、of soil ShiBianPo necessary protection.Firstly,a slope failure forms and reasonsEmbankment slope of the slump is one of the most common roadbed disease, according to slope soil category damage reason and scale is different, the main failure form of slip party peel and broken down landslide collapse

16、four slip party is due to a small soil slope moves down along the soil formed, namely the slope of thin surface soil slip under, it is often due to rainfall precipitation and flowing water erosion caused by improper slope or construction of the landslide is refers to the part of the gravity of soil

17、slope under one of the sliding surface sliding, mainly because of the soil slope of embankment caused by inadequate stability of landslide is the main reason of the side slope steep or spend change clearly feet are hollow, or filling levels arrangement inappropriate, etc.; Cut slope is the main reas

18、on of the landslide slope height and slope and natural geotechnical levels of nature does not adapt spalling and broken down is refers to the slope rock weathering surface. In different kinds of external environment under the influence of the top rock slope and peeling off from the destroy form of c

19、ollapse usually refers to the larger stones out along the slope surface slope and tumble down. ，Embankment slope protection design principlesHighway slope distribution along the road of the range, the destruction of the environment of natural range, if in the protection, and can also pay attention t

20、o protect the environment and create the environment, the adoption of appropriate green protective method, can make highway has safe and comfortable and beautiful in harmony with the environment and other characteristics, which will create considerable economic benefit and social benefit of ecologic

21、al benefit so, slope design should follow the safety of soil and water conservation and restoration of natural green environmental protection of the way the design principles，embankment slope protection method1.The plant grass protection plant protection in the slope is planted on grass or trees to

22、slow down the slope of flow velocity, the use of plant root consolidation of surface soil slope to reduce erosion, so as to achieve the function of the slope protection plant protection not only can beautification highway environment, adjust the temperature wet slope, consolidation and the stability

23、 of the slope play a role, and simple economic. Plant grass protection should choose the root system developed stem short and leafy drought tolerant grass seed, it is strictly prohibited to the growth in mud to clear the implanted directly into the grass slope protection method are as follows: first

24、ly, in the soil slope surface water mixing with seed fertilizer, direct sprayed in the slope surface, the advantage is simple convenient construction cost is low, but vulnerable to wind erosion; Secondly, in dressing good slope surface, will clay fertilizer water with seed mixture of spray directly

25、injection machine in the slope, and the soil adhesion, seed will rooted in soil slope, forming overall protection of the two methods in plant grass at the initial stage, the rain should be from erosion, fabric covered, because no slope reinforcement treatment in heavy rains and runoff erosion of the

26、 slope easily result in damage, and therefore should be in commonly 3-5 months each year.2. Engineering protection engineering protection is mainly aimed at not suitable for the growth of plant soil slope excavation or weathering fill joints growth of serious adverse rock embankment slope, take engi

27、neering protection measures that is setting artificial slope protection.3. Do PianShi build by laying bricks or stones do build by laying bricks or stones PianShi is designed to protect the slope from atmospheric precipitation and runoff violations, and protect water embankment slope from flow erosi

28、on of severe cold wet or sections of long-term bear active earth pressure area should not be commonly use dry build by laying bricks or stones PianShi protection, and can be used in the soil slope under the slope protection, slope of 1:1. 5-2-1.4. Pulp PianShi plasma build by laying bricks or stones

29、 PianShi build by laying bricks or stones set in immersion embankment and possible washed the soil slope surface slope, should do well in the combination of drainage and protection, otherwise not be used as the water velocity is (such as in 4-5 m/s), wave action is stronger, and rivers flow and othe

30、r wood may have hit content to wait impact, appropriate USES plasma build by laying bricks or stones PianShi protection, when necessary and water retaining wall or HuMianQiang also set pulp PianShi build by laying bricks or stones advantage is good durability slope protection, which is suitable for

31、the protection of the different control slope rock layer and different locations of the slope, and moderate cost, it is applicable to the general up and down the slope slope5. Arch type grid protection this protection way been overcome the QiShi protection drainage anti-scouring ability weak and the

32、 large amount of work the characteristics, the maximum slope greening, appearance is better, in long lines of the high fill slope section, can achieve beautification greening double effect, road protection in recent years is the commonly used method shortcoming is one of the more tedious;, labor str

33、ength, strict requirements on slope surface, within the filled soil arch must be planting grass or other engineering protection, or to be rain erosion.6. Precast block slabs protection this is the current highway slope protection method widely applied one, because of the specifications of the precas

34、t block consistent, easy construction, neat appearance, minimizes the slope protection on plant grass greening dependence, even if the slope greening the result is bad, it is not easy to cause too serious erosion phenomenon, so, at the moment, most of the highway that way, defect is cost is high, di

35、fficult construction.7. Jet concrete protective jet concrete method into meat spray method and shotcreting method for directly spray method, high standard in the formation of the mortar injection roughly sheared off, make easy to loose particles slope stably, ensure running and pedestrian safety it

36、used for surface layer of rock bolting and easy to loose by law, the working principle is to use sliding body will be fixed in the mountain, the mountain to the constraints of sliding, and in the sliding body surface anchor head and sprayed concrete use steel mesh, sliding body surface formation in

37、reinforced concrete board body structure, so can will loose rock fixed for a whole, in order to achieve the purpose of cure landslide shotcreting act applies to most of the rock soil and rock soil and other geological structure mountain and produce landslide location, it can prevent the generation of landslide early as long as produce sliding area is not very big, Sliding layer is very thick,