18.Cau tao mai doc.Neu dien hinh cau tao mai ngoi.

1. Tam lop

Tam lop co the la ngoi, tam ton, tam fibroximang, tam betong, tam giay dau. Tac dung

chinh cua no la bao che va bao ve cho cac bo phan ben duoi dong thoi trang tri kien

truc cho ngoi nha.

2. He thong ket cau mang luc cua mai doc

Vat lieu che tao ket cau mang luc cua mai doc thuong lam bang go, thep, gach da

hoac betong cot thep duoi nhieu hinh thuc khac nhau: cau phong , vi keo hay bang cac

tam lap ghep.

*. Ket cau tuong thu hoi chiu luc :

Dung tuong ngang chiu luc xay thu hoi lam ket cau chiu luc chinh.

Tren tuong thu hoi gac xa go (don tay), tren xa go gac cau phong (ren, rui) hoac lat

van go va tren cau phong dat cac lito (me, lach) , cuoi cung la lop lop .

Vat lieu lam xa go : go hoac be tong cot thep.

Xa go duoc bo tri nhu dan cua san nha : o giua noc tren cung la xa go noc, o duoi

cung doc theo duoi mai la xa go mai dua. O cac vi tri dat xa go co cac mieng dem de

dam bao luc phan bo deu len dau tuong.

Vi tri cua xa go mai dua phu thuoc vao kich thuoc vuon ra khoi tuong cua mai

dua:

+ Khi mai dua ra < 50cm : dat truc tiep len tuong doc ngoai.

+ Khi mai dua ra > 50cm : tua tren cac dam cong xon duoc lien ket vao tuong

bang bulong neo giu .

Uu diem : ket cau don gian, kinh te.

Nhuoc diem: chieu rong cac gian bi han che (<= 4m) , neu can phai rong > 4m thi

nen dung ket cau vi keo, cau phong hoac dam.

*. Ket cau cau phong hay dam nghieng :

Cau phong la cac dam go duoc dat truc tiep len nhung dam go dem duoc dat doc

theo tuong ngoai .

Ap dung khi be ngang nha khong lon lam va giua nha co kha nang tao cac goi tua .

Co the lam mai 1 doc hoac 2 doc.

Tiet dien 80 x 100 - 80 x 150.

*. Vi keo :

- Mot so hinh thuc vi keo pho thong

Theo yeu cau cau tao ma vi keo co the lam bang go, thep, betong cot thep.Co

truong hop vi keo duoc lam bang go va thep, trong do thep chiu keo con go chiu nen

va uon.Vi keo thep va betong cot thep phu hop voi nhip nha lon, co yeu cau chiu lua

va do ben vung cao.

Theo hinh thuc co dan vi keo tam giac, hinh thang, hinh da giac. Khau do cua vi

keo co the chon tu 6-9m doi voi vi keo go, thep; 9-18m doi voi vi keo betong cot thep,

thep va >18m doi voi vi keo thep. Khi chon vi keo phai can cu vao chieu dai nhip, yeu

cau su dung cua phong oc, tai trong tac dung len dam, cac yeu cau ve tham my cung

nhu yeu cau ve tham my cung nhu yeu cau ve phong chay.

Trong xay dung dan dung vi keo tam giac duoc dung pho bien hon ca.Vi keo tam

giac bao gom cac thanh keo ( canh thuong) nam o phia tren, qua giang ( canh ha) nam

o phia duoi, thanh chong dung, thanh chong xien. duoc lam go hoac hon hop thep, go.

- Bo tri ket cau vi keo :

Tren mai doc co 3 phan chinh la : bo phan dau nha, bo phan giua nha va bo phan

noi tiep. Bo phan dau nha va giua nha co cau tao don gian va hinh thuc it bien hoa .

Bo phan noi tiep co cau tao phuc tap voi cac hinh thuc noi tiep : noi tiep song song,

noi tiep chu T, noi tiep chu L.

He thong ket cau vi keo cung theo do gom 3 bo phan: bo phan dau hoi, bo phan

giua nha va bo phan noi tiep.

• Ket cau doan giua nha :Dan vi keo

Khoang cach giua cac vi keo tu 3 - 6m tuy thuoc vat lieu lam vi keo va xa go la

go hay thep.

Tiet dien cac thanh cua dan tuy thuoc khau do cua vi keo. De tiet kiem vat lieu

thi giam khau do vi keo. Cho nen khi bo tri vi keo can chon khau do ngan nhat, can

tan dung cot hoac tuong lam goi tua trung gian.

Doi voi nha hanh lang giua co the loi dung tuong hoac cot hai ben hanh lang

lam diem tua , nhu vay vi keo co the nho lai hoac su dung ban vi keo, 2 nua vi keo

can duoc lien ket voi nhau bang he giang.

Cac vi keo can phai lien ket on dinh tung cap mot bang cac thanh, he giang

cheo. Dong thoi phai cau tao lien ket giua cac vi keo voi tuong chiu luc hoac cot

chiu luc de tao thanh he ket cau vung chac.

Cau tao lien ket giua cac vi keo voi goi do can phan bo luc deu, tranh luc tac

dung cuc bo, co the dung go dem dau keo. Goi do la lien ket di dong o dau vi keo

tranh noi luc sinh ra do dan no cua vi keo.

• Ket cau doan dau hoi :

Nha 2 mai doc :

Truong hop mai khong dua ra khoi tuong : tuong dau hoi duoc nang cao de che

mai, phai chu y cau tao mu bao ve (duong bo noc) dong thoi chong tham va chong

dot doc theo duong tiep giap giua mai va tuong.

Truong hop mai dua ra khoi tuong: su dung pho bien nham bao ve tot tuong

dau hoi, chi can dat xa go nho ra khoi tuong, con cac bo phan khac duoc cau tao

giong nhu doan giua nha .

Nha 4 mai doc :

Ket cau doan dau hoi bao gom ket cau chiu luc o vi tri giao tuyen cua 3 mat

doc che doan dau hoi nha . Ket cau chiu luc la cac ban vi keo va dam nghieng ..

Noi chung ket cau kieu nay co cau tao phuc tap .

Tuy theo khau do L cua vi keo ma co the bo tri theo 3 phuong an :

+ Khi L < 6m : chi lam vi keo goc .

+ Khi 6m < L <= 9m : vi keo goc ket hop voi ban vi keo trung gian.

+ Khi 9m < L < 12m: vi keo goc ket hop voi ban vi keo hay dam nghieng.

Cac vi keo goc co cau tao nhu vi keo thuong. Can chu y cau tao lien ket giua

cac ban vi keo, vi keo va cac thanh qua giang. Chu y bo tri phan tan cac diem goi

tua cua cac vi keo khong de tap trung nhieu tai mot nut.

• Ket cau doan noi tiep :

Co nhieu giai phap bo tri ket cau doan noi tiep . Mot vi du ve ket cau doan noi tiep

hinh chu T theo 2 phuong phap bo tri tuy thuoc khau do vi keo :

+ Khi khau do lon noi tiep voi khau do nho : ap dung phuong cach xa go gac

len xa go voi xa go khau do nho dat tren xa go co khau do lon .

+ Khi 2 khau do bang nhau : ap dung phuong cach vi keo gac len vi keo, vi

keo a co mot dau gac len tuong , dau con lai gac len vi keo b , o vi tri giao

tuyen giua cac mat doc dat dam nghieng c, neu khau do lon thi co the thay dam

nghieng bang ban vi keo .

• Lien ket cac cau kien:

Cac moi lien ket giua cac cau kien cua vi keo duoc goi la mat keo, tuy theo vi

tri ma duoc goi rieng la mat goi, mat trung gian, mat dinh, mat giua duoi.

Doi voi vi keo go, cac cau kien chiu keo duoc cau tao lien ket chot bang go

cung, bang kim loai nhu bulon, dinh hoac mong ghep, cac cau kien chiu nen duoc

cau tao lien ket mong deo chinh dien vuong goc hoac phan giac co mot rang, hai

rang hoac mong deo chinh dien loai ty

Doi voi vi keo thep, cac cau kien duoc cau tao lien ket va noi bang bulon, dinh

tan hoac han truc tiep hay gian tiep voi tam thep trung gian tuy theo vi tri va su

lam viec cua cac thanh tai nut lien ket

• Bo phan do tam lop :

Xa go: dat tren thanh keo va duoc giu on dinh boi con bo. Tiet dien cua xa go

bang go co the chon 6 x 12cm , .. , 12 x 20cm .

Khi mai dua < 60cm , xa go mai dua co the dat truc tiep len dau qua giang; khi

mai dua > 60cm thi xa go dat tren conson.

Khoang cach giua cac xa go thuong tu 1 - 2m.

Xa go nen gac len mat vi keo de thanh keo khong bi uon

Cau phong :neu dung tam lop loai nho thi tren xa go co dat cau phong de chiu

lito do tam lop .Tiet dien cua cau phong go 5 x 5cm, 5 x 6cm dat theo chieu doc

cua mai va cach nhau 50 - 60cm.

- He thong giang vi keo:

Tac dung: cac dan vi keo phang rieng le ngoai viec duoc lien ket voi nhau bang

cac xa go go ma con phai cau tao lien ket bang thanh giang, thanh chong.v.v.... duoc

goi chung la he giang nham tao thanh mot he ket cau khong gian on dinh, bao dam cac

tac dung:

Lien ket khong gian cac mat vi keo, bao dam on dinh ngoai mat phang cho cac

thanh canh chiu nen

Chiu cac luc khong nam trong mat phang cua dan vi keo, truyen di cac luc di

xuong cot , mong

Tiet dien thanh chong 50 x 100mm. Khi khau do >15m thi lam 2 he giang chong

• He giang trong mat phang mai: Day la he giang chu yeu nhat bao dam tinh

chat bien hinh cua cong trinh, bao dam on dinh cua toan dan vi keo cung nhu

cua thanh canh nen. Tuy theo chieu dai nha , do lon cua dan vi keo va ket cau

tuong dau hoi ma co the cau tao he giang mai nhu sau:

Truong hop chieu nha dai: <20m va co tuong dau hoi cung co the chiu duoc luc

ngang( tuong gach >22cm) thi co the dung ngay xa go de lam giang, voi dieu kien

xa go phai duoc cau tao lien ket chat vao thanh keo( canh tren cua dan vi keo)

cung nhu tuong dau hoi.

Truong hop tuong hoi khong du cung de chiu duoc luc ngang cung nhu khi nha

dai qua ( khoang cach giua cac tuong ngang cung >20m ) thi phai tao ra nhung

khoi cung o hai dau nha va doc chieu dai nha, cach nhau khong qua 20m de lam

tua cho cac xa go go on dinh cac dam vi keo khac o khoang giua . Khoi cung gom

hai dan vi keo canh nhau, thanh keo duoc noi nhau bang cac thanh giang cheo chu

thap , tao thanh mot dan nam nghien. Thanh giang cheo dong dinh truc tiep vao

thanh keo hoac qua cac dai thep mong, cho giao nhau giua giang cheo va xa go

cung can lien ket chat

• He giang dung

He giang dung co tac dung co ket cho cac mat cua canh duoi ( qua giang) khong

venh khoi mat phang cua gian vi keo, bao dam cho dan co vi tri thang dung , dac biet

khi co gio lon, nen cung duoc goi la giang gio.Giang dat trong mat phang thang dung

o giua dan vi keo noi tung doi vi keo vao nhau va co the cach vai ba gian thi bo tri

mot he giang dung. Khong nen lam giang dung lien tuc suot chieu dai giang vi khi do

neu mot dan vi keo chinh bi pha hoai vi nguyen nhan nao do thi se chuyen luc sang

cac vi keo lan can va co the gay pha hoai day chuyen.

Khi nhip cua dan vi keo kha lon(<15m) thi phai lam 2, 3 he giang dung trong cac

mat phang thanh dung khac cua dan vi keo

He giang dung bao gom hai thanh thep chu thap va mot thanh ngang noi cac canh

duoi (qua giang) thanh cheo bat bulong vao thanh dung cua dan vi keo chinh ( neu

thanh nay bang go ) hoac bat bullong vao xa go vao canh duoi cua dan vi keo chinh,

thanh cheo con duoc lam bang thep tron, bat vit vao canh dan vi keo.

Tiet dien cua thanh giang dung duoc chon theo cau tao, kiem tra, thanh go co do

mong <20cm, thanh thep tron co duong kinh 12-16cm.

Noi chung viec bo tri va cau tao dung cach he giang cua mai nha co y nghia quyet

dinh den su lam viec an toan cua he mai , khi thiet ke can quan tam dat biet.

*)). Mai lop ngoi

Quy cach tam lop :

Ngoi duoc san xuat voi nhieu loai kieu va kich co va duoc lam bang vat lieu: dat

nung, vua xi mang hoac thuy tinh.

Theo hinh thuc co the phan loai:

• Ngoi may : la loai ngoi co ranh. Co 2 kieu : kieu 13 vien cho 1m2 co kich co

400 x 240 x 35mm va kieu 22 vien cho 1m2 co kich co 220 x 300 x 30mm .

• Ngoi moc: la loai ngoi phang thuong dung 70 vien / m2.

• Ngoi am duong hay ngoi long mang .

• Ngoi up song noc: ngoi bo hinh mang 1/2 tron hay chu V

Phuong cach lop :

Cau phong la cac thanh go co tiet dien hinh vuong hoac hinh chu nhat dat vuong

goc voi xa go duoc lien ket voi xa go bang dinh. thong thuong khoang cach 2 xa go

nho hon 2000 thi khong cach cau phong la 500 va co tiet dien 50x50.

Truoc tien co dinh bang dinh cac thanh lito 2 x 3cm hoac 3 x 3cm khoang cach 25

cm - 35cm vao cau phong. Ngoi lop tu duoi len va noc nha lop ngoi bo. Chieu rong ke

len nhau cua 2 vien ngoi noc khong duoc < 5cm va co the dung them vua xi mang gan

de phong dot .

Khi lop cac vien ngoi duoc bo tri so le nhau. De giam kha nang ngoi bi truot hang lito

cuoi cung duoc dong lito kep va cach hang lito tren la 180cm - 280cm, 2 hang ngoi cuoi

cung phai duoc buoc vao lito bang day thep. O cac hang tren cu cach mot hang buoc mot

hang .

De de phong hien tuong nuoc mua co the hat qua khe ho dot vao trong nha khi co

gio manh , dung vua trat cac khe ho hoac lot mot lop chong dot thu 2 bang vat lieu

nhe nhu giay dau o phia duoi lop ngoi, do doc cua mai lop ngoi co the chon trong

pham vi tu 25o - 45o thuong chon la 30o hay 60%.

Uu diem va nhuoc diem cua mai lop ngoi :

Uu diem: co tinh chong chay cao, chong tac dong hoa chat tot, ben vung, su dung

duoc vat lieu dia phuong, gia thanh ha nen duoc ap dung pho bien.

Nhuoc diem: trong luong nang, kich thuoc nho khong phu hop voi cong nghiep

hoa xay dung, goc nghieng cua mai lon nen lam cho ket cau vi keo them phuc tap