東風節(jié)制閘設計畢業(yè)設計說明書畢業(yè)設計說明書(含圖紙)

1、水閘畢業(yè)設計任務書1東風節(jié)制閘設計原始數(shù)據(jù)2設計總說明4第一章 水閘樞紐布置121.1 總體布置12水閘位置時應考慮的幾個因素131.2 結構布置13閘室的結構布置13兩岸連接布置14防滲排水布置14消能防沖布置15第二章 水閘的水力計算162.1 閘孔設計16上下游水位的確定162.1.2 閘孔尺寸設計182.1.3 堰型選擇192.1.4 閘墩厚度的選擇202.1.5 水閘泄流能力校核202.2 消能防沖設計212.2.1 節(jié)制閘泄流特點：212.2.2 消能設計條件212.2.3 水閘的消能方式22消力池設計23海漫設計28防沖槽設計302.3防滲排水設計31防滲設施布置31閘基防滲長度

2、校核342.3.3 排水設施的設計37第三章 閘室及地基的抗滑穩(wěn)定計算383.1閘室輪廓尺寸的確定38閘頂高程與閘門高度383.1.2 底板形式及尺寸39閘墩403.1.4 啟閉設備413.1.5 工作橋423.1.6 交通橋43各部分重量計算433.1.8 分逢與止水443.2 閘室穩(wěn)定計算44作用于閘室上的荷載和組合453.2.2閘室基底應力、抗傾及抗滑穩(wěn)定驗算47閘基深層滑動及地基沉降量計算52第四章 平面鋼閘門設計534.1平面鋼閘門的結構形式及布置53閘門尺寸的確定54主梁的形式54主梁的布置54梁格的布置和形式55聯(lián)結系的布置和形式55邊梁與行走支承554.2面板設計55估算面板厚

3、度55面板與梁格的連接計算574.3水平次梁、頂梁和底梁的設計574.3.1 荷載與內(nèi)力計算57截面選擇59水平次梁的強度驗算60水平次梁的撓度驗算60頂梁和底梁604.4主梁的設計61設計資料61截面選擇61截面改變63翼緣焊縫63腹板的加勁肋和局部穩(wěn)定驗算64面板局部彎曲與主梁整體彎曲的折算應力驗算644.5橫隔板設計65荷載和內(nèi)力計算65橫隔板截面選擇和強度計算654.6縱向聯(lián)結系設計66荷載和內(nèi)力計算66斜桿截面計算664.7邊梁設計67荷載和內(nèi)力計算674.7.2 邊梁的強度驗算684.8行走支承設計694.8.1.膠木滑塊尺寸確定69確定軌道底板的寬度69確定軌道底板厚度694.9

4、.閘門啟閉力與吊座計算69啟門力計算694.10.導向裝置設計704.10.1 止水704.11閘門啟閉力與吊座計算71吊軸和吊耳板驗算71第五章 翼墻的結構設計725.1 翼墻的結構設計72上游翼墻的結構設計73岸墻的結構設計75下游翼墻的結構設計76上游翼墻的防滲設施及下游翼墻的排水設施設計765.1.5 翼墻防滲和排水的布置76止水的結構形式和排水設備的構造77水閘畢業(yè)設計任務書一 畢業(yè)設計的目的和要求畢業(yè)設計是專業(yè)教學工作中的重要環(huán)節(jié)之一，通過設計實踐力求達到如下目的與要求：鞏固、加深、擴大所學的基本理論和專業(yè)知識，并使其進一步系統(tǒng)化。1 培養(yǎng)學生運用所學知識解決實際工程技術問題的能力

5、，要求掌握設計原則、設計方法和步驟。2 培養(yǎng)學生獨立思考、獨立工作的能力。通過畢業(yè)設計加強計算、繪圖、編寫設計文件、使用規(guī)范等方面的能力。二 畢業(yè)設計內(nèi)容1 根據(jù)基本數(shù)據(jù)及水閘樞紐的使用要求，確定水閘的樞紐布置及組成結構的型式與尺寸。2 針對水閘樞紐，進行水力計算、防滲設計和穩(wěn)定計算。對組成水閘的各構件進行結構計算及配筋設計。 3 平面鋼閘門設計。三 設計成果完成設計說明書及計算書各一份，工程設計圖紙4張。1 總體布置平面圖，（繪于地形圖上）；2 縱向剖面圖與平面布置圖；3 水閘上、下游立視和主要細部大樣圖；4 平面鋼閘門上、下游立視、側視及俯視圖（包括門槽及埋件、軌道、止水、止水座、護角），

6、材料表（將門葉構件依次編號逐項填入表中，包括名稱、形狀、規(guī)格、數(shù)量），說明。東風節(jié)制閘設計原始數(shù)據(jù)一 設計概況東風水閘位于我國北方A河右岸河畔上的一座中型節(jié)制水閘，其功用為攔蓄部分洪水，以補充地下水及解決農(nóng)業(yè)灌溉用水。二 工程簡況1 閘址位置：A河為一古老河道，彎彎曲曲，河道呈S彎狀；選S彎的兩個凸岸為閘址較為適當，優(yōu)點是地域開闊，工程布置在自然土基上，施工導流與主體工程施工無干擾，閘址基本在河道中心線上。其缺陷為上、下游連接段較長，工程量較大。2 工程規(guī)模：該水利工程按5年一遇洪水設計，20年一遇洪水校核，引渠邊坡m=2，縱坡i=1/4000,渠底高程46.8米，設計流量Q 設129.4立方

7、米秒。校核流量Q校=237立方米/秒，最高設計蓄水位51.6米，一次蓄水量50萬立方米，灌溉農(nóng)田面積3.5萬畝。三 地形情況閘區(qū)西部位于丘陵地區(qū)，西高東低，地面坡度為140011000，東部為沖積平原，地勢較平坦，地面坡度為1250014000。四 工程地質(zhì)情況在閘址范圍內(nèi)鉆孔5個，孔深20米，總進尺100.9米，取原狀樣5個，散狀樣24個，標準貫入試驗56個，作以上土樣的物理力學試驗及擊實實驗各一組。試驗表明：閘基處土層為河湖相沉積物，N63. 5=11,地質(zhì)自上而下劃分為五個工程地質(zhì)單元。第I 單元，表層為耕植壤土，厚1.0米，可塑。其下為壤土、黏土及砂壤土,總厚3.54.8米，底板標高在

8、46.947.3米之間。第II單元,自上而下為淤泥質(zhì)壤土、砂壤土、裂隙粘土，總厚度3.44.0米,底板高程在43.0643.08米，分布連續(xù)穩(wěn)定。第III 單元, 巖性主要為淤泥質(zhì)壤土,總厚2.54.2米，底版高程在39.340.3米,土質(zhì)均勻,可塑.有自然孔洞,中高壓縮性,頂部有零星分布的砂壤土,底部局部分布有黏土。第IV單元,巖性主要為砂壤土,夾薄層壤土,還有零星分布的細砂層,總厚度3.84.8米,底板高程35.636.8米。第V單元, 巖性主要為裂隙黏土和裂隙壤土,頂高程35.636.8米,分布穩(wěn)定,局部夾薄層粉砂。閘底板高程與河床齊平在46.8米處,相當于第II 工程地質(zhì)單元頂部,持力

9、層影響范圍內(nèi)的第II、III、IV、V單元土的壓縮性不均,一般土層為中偏低壓縮性,建筑物主要持力層地基土為軟塑的淤泥質(zhì)壤土及連續(xù)分布的裂隙土。勘探范圍內(nèi),地下水初見水位埋深3.54.3米，有微弱承壓性,施工時注意預降地下水位,防止II,III單元土層破壞。五 .水文氣象由水文分析,東風閘以上流域面積877.7km2,其中山區(qū)471.3 km2,平原406.4 km2,年徑流量95%年份有317萬立方米,扣除60%沿途水量損失及0.7的不均勻系數(shù),還有88.8萬立方米,滿足本閘一年一次蓄水量,保證灌溉效益。該區(qū)平均氣溫12度,年平均降雨量571毫米,最大降雨量1510毫米,最小降雨量129.5毫

10、米,70%集中在7、8、9三個月,多年平均蒸發(fā)量931毫米,該區(qū)風速一般在4m/s,最大風速13m/s,吹程150 m,無霜期平均220天。六 交通情況閘本身無專門交通要求,考慮農(nóng)田耕作及水閘自身施工運行要求設人行便橋。七 設計數(shù)據(jù)地基土壤物理力學性質(zhì)及力學指標 流限 WT=25.6% 滲透系數(shù) KT=1.1x10-6 m/s 塑限 WP=17.2% 凝聚力(室內(nèi)值) C=2T/m2 塑性系數(shù) IP=8 內(nèi)摩擦角(室內(nèi)值) =16 地基壓縮模量E Kg/cm2 濕容重 r 濕=1.75T/m3 含水量 W=31.3% 飽和容重 r飽.90T/m3 孔隙比 e=0.73 干容重 r干=1.6T/

11、m3地基承載力=15T/m2 浮容重 r浮=1.0T/m3閘底板與地基土摩擦系數(shù) f=0.35 夯實回填土內(nèi)摩擦角=25° 上下游引渠糙率 n=0.025 引渠底寬(上,下游) b=28m引渠邊坡系數(shù)(上,下游) m=2 混凝土容重 r=2.4T/m3鋼筋混凝土容重r=2.5T/m3設計總說明水閘是灌排工程的主要建筑物之一，它是一種利用閘門進行擋水或泄水的低水頭水工建筑物，既可控制流量又可調(diào)節(jié)水位。關閉閘門時，它可攔洪蓄水，擋潮或抬高閘前水位；開啟閘門時，又可泄洪排澇或?qū)ο掠魏拥阑蚯拦┧?。這次我們主要設計修建在平原河道上的節(jié)制閘。節(jié)制閘一般跨越河道修建，用于枯水期蓄水，抬高水位以供

12、進水閘取水，洪水期開閘泄洪。在渠系中一般位于支、斗渠分水口稍下游，跨越干、支渠修建，用于抬高干、支渠水位，供支、斗渠取水。本次設計主要分為以下六部分：1、分析資料及水閘樞紐布置已提供的資料是設計的基本依據(jù)，為使設計成果安全、適用、經(jīng)濟，首先應熟悉并分析各種資料，如地形、地質(zhì)情況，各有關高程，特征水位及相應流量等，然后根據(jù)閘址地形、地質(zhì)、水流等條件以及該樞紐中各建筑物的功能、特點、運用要求，確定樞紐布置，做到緊湊合理，協(xié)調(diào)美觀，組成整體效益最大的有機聯(lián)合體。2、水力計算 主要包括閘孔設計、消能防沖設計、防滲排水設計。閘孔設計首先根據(jù)上面擬定的水閘型式及設計流量，確定閘孔凈寬及適宜孔數(shù)。然后再驗算

13、初擬閘孔尺寸的過流量是否滿足泄流要求。消能防沖設計 為了消除水流過閘后的能量，設計了消力池、海漫和防沖槽。消力池：計算在設計蓄水位下，閘門在各種運行工況和不同開啟高度時的泄流量，確定是否設消力池。若需設置則根據(jù)消能條件，計算消力池深、長、底板厚度及所用建筑材料。海漫：消力池能消除水流50的能量，其余能量由海漫消除，根據(jù)水閘不同泄量的水力計算，布置海漫，確定長度及建筑材料。防沖槽：計算海漫末端河床沖刷深度，設計計算防沖槽斷面形狀、尺寸、確定拋石量及護坡砌置深度。防滲排水設計首先擬定水閘地下輪廓線型式，初步計算所需長度，然后依次確定閘室底板、鋪蓋長度及材料，設計反濾層及排水孔位置，最后計算閘基滲透

14、壓力，繪制滲透壓力分布圖。3、閘室的布置設計及閘室穩(wěn)定性計算閘室輪廓尺寸確定由水力條件及水閘功用，確定閘室總寬、閘頂高程、閘墩、閘門、底板的型式與尺寸，閘室上部結構的工作橋、交通橋、啟閉設備的型式與尺寸。閘室穩(wěn)定計算選取計算單元，計算作用于閘室的荷載，并按計算條件進行組合。分別按完建期，正常蓄水期，正常蓄水加特殊荷載組合三種工況進行閘室抗滑穩(wěn)定性和地基承載力驗算，并對地基應力分布狀態(tài)及沉降差進行計算分析，判斷水閘地基是否滿足承載力、抗滑穩(wěn)定和變形要求。閘基深層滑動及地基沉降量計算根據(jù)設計資料給出的土壤物理力學特性指標，驗算在荷載作用下基礎是否發(fā)生帶動一部分地基土向下游深層滑動，并確定是否進行地

15、基沉降量計算。4、兩岸連接建筑物岸、翼墻的結構型式，布置及穩(wěn)定性計算由閘室的結構尺寸及地基條件，確定岸、翼墻的平面布置型式，結構型式，斷面尺寸。按完建期和正常蓄水期兩種工況，對岸、翼墻的地基承載力，基底最大最小應力比值及基底面抗滑穩(wěn)定進行計算。 上游翼墻的防滲設施及下游翼墻的排水設施設計。5、閘室結構計算閘墩應力分析將閘墩視為固接于底板上的懸臂梁，以閘墩和底板的結合面作為計算控制面，分別按運用期（閘門關閉擋水）和檢修期（一孔檢修其它孔過水）兩種工況，計算中墩墩底水平截面垂直正應力、剪應力、門槽應力、墩底水平截面?zhèn)认驊Γ⒎治鲇嬎憬Y果，進行配筋設計。底板應力分析以閘門為界，將底板分為上下兩部分

16、，分別在兩部分中央垂直水流方向取單寬板條進行分析。按完建期和運用期兩種工況，計算作用于板條上的荷載。包括底板自重，中、邊墩及上部結構重，水重 ，揚壓力及不平衡剪力并對其進行分配，按彈性地基梁郭氏法查表計算，求得地基反力及計算板條各截面的內(nèi)力，分析計算結果進行底板配筋設計。6、平面鋼閘門設計門葉結構門葉結構布置：確定門葉結構所需的各種構件，數(shù)目及所在位置，梁格及聯(lián)結系的型式、連接方式，行走支承及邊梁的型式。面板設計：在充分發(fā)揮面板強度的前提下，設計一經(jīng)濟合理的面板厚度。并在主梁截面確定之后校核面板的局部彎曲與整體彎曲的折算應力強度。水平次梁、頂、底梁設計：均采用型鋼。由各構件的內(nèi)力，選擇各梁的截

17、面，并進行強度、剛度驗算。主梁設計：確定主梁數(shù)目、位置、截面型式，斷面尺寸，截面改變，翼緣焊縫設計及主梁局部穩(wěn)定驗算。豎直次梁及橫縱向聯(lián)結系設計：確定其型式及位置，由內(nèi)力計算選擇截面尺寸及強度驗算。邊梁設計：由行走支承確定邊梁結構型式，按構造要求設計邊梁，并對其危險截面進行強度校核。行走支承設計：確定其結構型式、尺寸，并進行強度驗算。導向裝置設計：確定反、側行走支承型式，位置及連接方式。止水、吊耳設計：確定止水型號及布置方式，由啟門力設計，吊軸及吊耳板尺寸并對吊耳板強度進行驗算。門槽埋設構件確定門槽各軌道型式，斷面尺寸，對主軌進行強度校核。確定止水座及門槽護角構件型式。閘門鎖室裝置設計。啟閉機

18、械選擇計算啟門力，確定啟閉機類型、型號。計算閉門力，校核是否應采取工程措施降門。吊具設計：由啟門力設計吊索。關鍵詞：水閘；閘室；平面閘門；防滲排水；主梁Design the leader The sluice is irriated and arranged one of the main buildings among the project,it is a kind of low flood peak water conservancy project builing utilizing the gate to block water or sluice, can control the

19、adjustable water level of the flow. While closing the gate, it can block the big conservation storage, the tide of the shelf or improving the water level in front of the floodgate, can release floodwater, drain flooded fields or supple water of the downstream river or the channel while opening the g

20、ate. We design the check gate built on plain and river mainly this time.The check gate generally crosses over the river to build, used in dry season conservation storage, redound water level for sluice fetch water, turn on floodgate release floodwater flood period. In canal is it prop up to lie in g

21、enerally among the department, lateral canal divide into water mouth low reaches slightly, use for redounding the water level of branch canal, for propping up, the lateral canal fetch waterThis design is divided into six following parts mainly:1.It is analysed that the materials and sluice pivot are

22、 fixed up. The materials that have already been offered are basic bases designed, in order to edable designing the achievement safe, suitable, economy, should be familiar with and analyse various kinds of materials at first, for instance topographical, geological situation, each about high Cheng, ch

23、aracteristic water level and corresponding flow, ect, then according to floodgate location, topography, geology, rivers, etc, terms and every building of function, characteristic, use demanding to confirm the pivot is decorateds of the pivot this, accomplish the structure compactness, rational, coor

24、dinates, beautiful.2.Water conservancy is calculated: Including floodgate hole design, is it can is it wash the design, prevention of seepage drain off water and design to defend to disappear mainly. The hole is designed in the floodgate give design flow definitely confirm according to sluice form a

25、nd materials that draft above floodgate hole clear width and suitable floodgate hole count at first, then checking computations plan floodgate hole size pass flow satisfied with the requirement of releasing floodwater for the first time. Disappear and can defend and print designing for dispel water

26、flow through energy of floodgate,is it disappear strength pool, sea overflow and defend and wash the trough to design. Disappear in the strength pool calculate in design water storage level under the terms, gate turn on in various kinds of form, operating mode of operation and hole of floodgate, one

27、 pair of holes is turned on symmetrically, three holes open and different flow of letting out while opening the height at the same time,confirm whether to need to set up and subdueing the strength pool or not. If is it design to need, want according to condition of can disappearing,is it disappear d

28、epth, strength of pool to calculate, thickness of the length baseplate and construction material used. The sea overflowing disappear strength pool can dispel rivers 50% energy,other energy all over the place to dispel from sea,according to different letting out amount of the sluice,confirm long degr

29、ee and construction material of sea. Defend and wash the trough calculate sea overflow end wash hole depth, is it wash trough section form and size to defend to design. The prevention of seepage drains off water and designs: Draft the underground outline line at first, confirm the length tentatively

30、, then confirm the floodgate room baseplate, length of the bedding and material sequentially, design and strain layer and drain off water in the hole position instead, calculate the base osmotic pressure of the floodgate finally, draw the distribution map of the osmotic pressure.3.The floodgate room

31、 is decorated and floodgate room stability is calculated: Confirm the size of the outline line of floodgate room confirmed the floodgate room is always wide by the water conservancy condition, floodgate high Cheng, floodgate mound, gate, pattern, size and floodgate room top structure job bridge, tra

32、ffic bridge, open and close pattern and size of the equipment of baseplate very. The floodgate room is calculated steadily choosing the unit of calculating, build one according to finishing, normal conservation storage one, normal conservation storage issue add special to is it make up three opeerat

33、ing mode checking computations floodgate room resist slippery stability and ground bear the weight of strength checking computations to load, distribute state and subside to ground stress difference carry on computational analysis, judge sluice ground meet strength of bearing the weight of, is it sl

34、ip steady and out of shape requirement to resist. The deep layer of floodgate room is slipped and the subsiding amount of ground is calculated according to design soil physics characteristic index that materials provide, checking computations foundation is it drive some ground soil slip to the low r

35、eaches to happen under loading function, confirm whether to carry on the subsiding amount of the ground to calculate or not.4.Tow sides join building-bank,structure pattern, wing of wall, assign and the stability is calculated: By physical dimension and ground terms, floodgate of room, confirm bank,

36、 level, wing of wall assign the pattern and size of section.Building an two kinks of operating modes of one and normal conservation storage according to finishing, the ground on other bank, wing wall bears the weight of strength, basis heavy minimum stress ratio count bottom surface of the base is i

37、t calculate to go on steadily to slip to resist most.Facilities of prevention of seepage in the wing wall of the upper reaches and pumping equipment on the downstream wing wall are designed.5.The structure of floodgate room is calculated: Mound stress analysis of the floodgate: Regard as floodgate f

38、irm to connect cantilever beam at baseplate by mound, regard the combination surfaces of the mound of the floodgate and baseplate as and calculate the chain of command, separately according to use issue (gate is it block water to shut off ) and overhaul issue two kinds of operating modes , mound ver

39、tical direct stress of horizontal section, shearing stress, trough stress of the door, mound bottom level sectional side direction stress of mound bottom while calculating, analyse result of calculation, is it mix muscle design to go on. Stress analysis of the baseplate: Make gate as the boundry, di

40、vide baseplate into two part from head to foot, fetch single wide lath analyse in two part central vertical rivers direction separately. Accord to finishing and building one and using the operating mode of an improved variety, calculate the load on function and lath. Including the baseplate conducts

41、 oneself with dignity,china, mound and top structure are heavy, raise pressure and uneven to cut strength and is it assign to go to it, France check the watch calculates according to elastic ground roof beam guo, try to get ground and calculation lath each sectional internal force against strength,

42、is it carry on baseplate mix muscle design to analyse.6.The level gate is designed: Leaf structure of the door. The layout of the structure of leaf of the door:Confirm door leaf various kinds of component structure need, figure and position , Ge Liang and pattern, way of connecting, connection of de

43、partment, pattern of walking and supporting and roof beam. The panel is designed :On the premise of giving full play to the intensity of the panel, design one thickness of panel with rational economy. And check some and crooked intensity of conversion stress with crooked whole of the panel after the

44、 girder section is confirmed. Level roof beam once, carrying, the botttom roof beam is designed: Adopt the section steel.By the internal force of every component, choose the section of every roof beam, carry on intensity, rigidity checking computation. The girder is designed: Confirm girder figure,

45、position, sectional form, the size of section, the section changes, wing reason welding seam design and some steady checking computations of girder. Vertical roof beam once and horizontal vertical connection department design:Confirm its pattern and position , is calculated and chosen sectional size

46、 and intensity checking computations by the internal force. The roof beam is designed:Is it confirm to support to walk roof beam structure patern is according to construct requirement design roof beam, and carry on the intensity to check to its dangerous section. Walk and support designing: Confirm

47、its structure pattern, size carry on intensity checking compitation. Lead the device to design: Confirm the inside out, side and walk and support the pattern, the position and way of connecting. Stagnant water, lifting lug are designed:Confirm the type of the stagnant water and assign the way, is op

48、ened door strength to design, hang the axle and board measurement of the lifting lug and carry on checking computations to the intensity of the lifting lug board. The door trough is buried the component underground. Confirm every track pattern of the door trough, the size of section, carry on the in

49、tensity to check to the main rail . Confirm stagnant water seat and door trough protect the horn component pattern.Lock the room device to design in the gate. Open and room device to design in the gate. Calculate and open the strength of the door, comfirm the type of headstok gear, type. Calculate a

50、nd close the strength of the door, should take the project measure to lower the door to check. The hoist is designed: Opened door strength and designed the sling.Key word: Sluice; floodgate room; level gate; prevention of seepage drain off water and design to defend to disappear; girder第一章 水閘樞紐布置1.1

51、 總體布置本設計為節(jié)制閘，一般跨越河道修建，故又稱為攔河閘。它是一種利用閘門進行擋水或泄水的低水頭建筑物，既可控制流量又可調(diào)節(jié)水位。關閉閘門時，它可攔洪蓄水，擋潮或抬高閘前水位；開啟閘門時，又可泄洪，排澇或?qū)ο掠魏拥阑蚯拦┧?。這次我們主要設計修建在平原道上的 節(jié)制閘。節(jié)制閘一般跨越河道修建。用于枯水期蓄水，抬高水位以及供進水閘取水，洪水期開閘泄洪。在渠系中一般位于支、斗渠分水口稍下游，跨越干、支渠修建也稱節(jié)制閘。用于抬高干、支渠水位，供支、斗渠取水。閘址一般應設置在河道直線段上。閘址處于上下游河道直線段長度均不短于510倍水面寬度，且不宜小于300m。壩址選擇是水閘規(guī)范設計中的一項重要工作，

52、閘址合適與否，不僅涉及到水閘建設的成敗，并且關系到整個地區(qū)的經(jīng)濟發(fā)展，因此對閘址選擇的工作應十分重視。水閘的類型較多，按其任務不同，可分為以下幾類;<1> 進水閘:為了農(nóng)田灌溉或其他水利事業(yè)的需要，進水閘往往建在河道，水庫或湖泊的岸邊，用于引水灌溉，發(fā)電或其他進水需要而控制流量。<2>節(jié)制閘：由于農(nóng)田灌溉，發(fā)電引水或改善航運要求，常需橫快河道或渠道修建水閘，以控制閘前水位和過閘流量，這類水閘成為節(jié)制閘。河道上的節(jié)制閘也也稱為攔河閘。在洪水時期，攔河閘還起排泄洪水作用。<3>擋潮閘：濱海地區(qū)的河流都受潮水影響，為了防止海水倒灌而抬高內(nèi)河水位，常在入海處河口附近

53、修建水閘，即為擋潮閘。漲潮時關閘，防止海水倒灌；當內(nèi)河水位過高落潮期間開閘排水。擋潮閘的特點，是承受雙渣向水頭，而且閘門啟閉頻繁。<4>排水閘：為使低洼地區(qū)大的漬水通過排水渠排入江河或湖泊，常需在排水渠末端設置水閘，這當河道類水閘稱為排水閘。排水閘除開閘排水外，在枯水季還可向內(nèi)引水灌溉；洪水時可關閘擋水，防止外水倒灌，也可蓄水灌溉。特點是：是承受雙向水頭。<5>分洪閘：當河道遭遇洪水而對下游可能造成洪災時，可將部分洪水泄入湖泊或洼地以消減洪峰。在分洪道首部需設置水閘，即為分洪閘。分洪閘常建于河道的一側，用來將超過下游河道安全泄量的洪水泄入分洪區(qū)或分洪道。<6>

54、;沖沙閘（排沙閘）：沖沙閘（排沙閘）建在多泥沙的河流上。用于排除進水閘，節(jié)制閘或渠系中沉積的泥沙。此外，還有為排除冰塊，漂浮物等而設置的排冰閘，排污閘等。水閘位置時應考慮的幾個因素地基條件 是影響水閘總體布置的主要因素之一應盡可能選擇土質(zhì)密實，均勻。壓縮性較小和承載能力較大的良好地基。此外，由于閘基土質(zhì)的抗沖能力直接影響單寬流量的選擇和閘后消能防沖設備的設計，而地下水位的高低及承壓水的有無對地基的穩(wěn)定性和施工期的排水措施也有所影響，故在選擇閘址時應考慮這些條件。水流條件 是另一主要因素閘的位置應使進閘和出閘水流平順，防止上，下游 產(chǎn)生有害的沖刷和淤積。施工、管理條件 也是閘址選擇時要考慮的一個

55、因素要求有足夠?qū)拸V的施工場地，并且盡可能使土方工程量最小。當水閘是整個樞紐的一個組成部分時，應就樞紐工程總體布置做方案比較，得出水閘最優(yōu)位置，以達到技術上先進與經(jīng)濟上合理的要求。1.2 結構布置閘室的結構布置水閘一般由上有連接段，閘室，下有連接段三部分組成。水閘的主體是閘室，其結構型式是多種多樣的，主要取決于泄放水流的方式以及閘門的構造和操作方式。按照閘室的泄流特點分類，可以分為以下幾種型式：1.堰流式閘室當閘門全開時過閘水流具有自由水面的水閘成為溢流式閘室，也稱開敞式閘室。一般堰檻高程較高，擋水高度較小的水閘都采用這種型式，依靠閘門擋水。當閘門全部打開時，水閘的過水面積和泄流量都隨水位的抬高

56、而增大，對于需要泄放洪水的攔河閘和分洪閘來說，這是一個很大的優(yōu)點。2.孔流式閘室當閘門全開時，自由水面仍受阻擋，水流只能通過固定洞孔泄入下游，稱為孔流式閘室，也成為封閉式閘室。當閘檻高程較低，閘室高度較大，需要泄放或取用底層水流時，常采用這種型式。一般把閘室頂部封閉。例如設置胸墻擋水，底部設置孔口泄水，這樣可以減少閘門尺寸。這種泄流方式最適合于沖沙閘的工作條件，有其突出的優(yōu)點。3.混合泄流式閘室這是一種既具有面流溢流能力，又具有底孔泄流能力的閘室結構。構造上分為上下兩層，分別裝設閘門。開啟上層閘門，利用面層溢流泄放洪水和漂流物。開啟下層閘門，則利用底孔沖刷閘前淤泥的泥沙。這種類型的閘室多用于攔河節(jié)制閘或引水系統(tǒng)的進水閘上。有時在特別軟弱的淤泥質(zhì)地基上建閘，為了加強閘室的橫向剛度，借以減小地基的不均勻沉降和閘