buniyaad

ek chhote ghar ki neenv kam gahari banaani padti hai jabki bahumanjila bhavanon ki neenv bahut gaharaai tak le jaayi jaati hai.

deevaar, khanbhe tatha bhavan aur pulon ke aadhaarastanbhon ka bhaar unki neenv athva buniyaad (Foundation) dvaara pruthvi par vitrit kiya jaata hai. at: nirmaan kaarya mein buniyaad, bahut mahatvapoorn ang hai. agar buniyaad kamjor ho, to poore bhavan athva pul ke bhaaravaahan ki shakti bahut kam ho jaati hai. agar buniyaad ek baar kamjor rah gayi, to baad mein use sudhaarana praaya: asambhav sa hi ho jaata hai. at: buniyaad ka abhiklp (design) bahut dakshata se banaana chaahiye.

neenv ka vishesh prayojan yeh hai ki vah oopar se bhaar ka baraabar se bhoomi par is prakaar vitrit kare ki vahaaain ki mitti (athva chattaan) par usaki bhaaradhaari kshamata se adhik bojh na pade, naheen to mitti ke baithane se bhavan ityaadi mein daraar padne ka bhaya rahata hai. neenv ke abhiklp ke liye vibhinn prakaar ki mitti athva chattaanon ki bhaaradhaari kshamata ka gyaan aavashyak hai. nimnalikhit saarani mein bhinn bhinn prakaar ki mittiyon ki bhaaradhaari kshamata di gayi hai -

kramaank jameen ki kism bhaaradhaari kshamata
(tan prati varg foot)
1 kaali mitti 1/2 se 1/4
2 reteeli mitti 3/4 se 1
3 ravedaar kankad aur baaloo mishrit mitti 1.5 se 2
4 nam, saadhaaran roop se kasi hui mitti 1 se 1.5
5 sookhi chikni mitti 2 se 3
6 bahut kadi chikni mitti 3 se 4
7 baareek baalukaamishrit mitti 1 se 2
8 drudheebhoot baaloo (compact sand) 3 se 4
9 moti baaloodaar mitti (coarse sand) 1.5 se 2
10 chattaan 10
11 kathor chattaan 12 se 15
12 bahut kathor chattaan 20 se 30

tippani-

(1) pruthvi ki satah se gaharaai jitni badhegi saadhaaranat: mitti ki bhaaradhaari kshamata bhi gaharaai ke hisaab se badhti jaaegi.

(2) saadhaaranat: paani ki nami se mitti ki bhaaradhaari kshamata kuchh kam ho jaati hai. iseeliye adhiktar bhavanon ki neenv jameen se kam se kam teen chaar foot gahari rakhi jaati hain, jisse varsha mein nami ka asar is gaharaai par bahut kam ho jaata hai. aisi jameen ki jahaaain paani bhara rahata hai, bhaaradhaari kshamata ausat se thodi kam leni chaahiye. bade bhavan tatha pul ityaadi ke liye mitti ki poori jaaainch mitti jaaainchanevaali kisi prayogashaala dvaara kara leni chaahiye.

neenv ki dijaain

neenv ki dijaain mein sabse aavashyak iski chaudaai hai, jiske dvaara neenv par aanevaale kul bojh ko vah jameen par is prakaar faila de ki jameen par bhaar usaki sahanashakti se adhik na ho.

agar jameen ki bhaaradhaari kshamata (athva sahanashakti) "s" hai tatha kul bhaar (neenv ke bhaar ko bhi lekar) neenv ki prati foot lanbaai par "bh" hai, to neenv ki chaudaai "ch" nimnalikhit sameekaran se nikaali ja sakti hain :

ch = bh / s

neenv ki gaharaai

yeh rainkin ke nimnalikhit sameekaran se praapt ki ja sakti hain :

g = (s / a) * (1- sin q) / (1 + sin q)

ismein s = jameen ki bhaaradhaari kshamata, a = int athva patthar ya kankreet ka, jisse neenv banegi, prati varg foot bhaar tatha q = vah kon, jismein mitti apne aap praakrutik dhang se ho jaati hai (angle of repose of soil).

praaya: bhavananirmaan mein uparyukt sootr dvaara jo neenv ki gaharaai aaegi, vah bahut thodi hogi. saadhaaran mitti mein neenv adhiktar teen, chaar foot gahari rakhi jaati hai.

saadhaaranat: bhavananirmaan mein tal mein choona ya cement kankreet aur uske oopar int ki chunaai ki neenv mein buniyaad ko failaane ke liye int ki chunaai ke har radde 2.25 inch ka khasaka chhodkar banaaya jaata hai.

is prakaar ki neenv ke atirikt prabalit cement kankreet (reinforced cement concrete), jhainjhareedaar neenv (grillage foundation), bededaar neenv (raft foundation) tatha ulati daat ka neenv (reversed arch foundation) ityaadi bhi neenv ke bhinn bhinn prakaar hain. yahaaain par unka poora vivran dena sambhav naheen hai.

neenv ka nirmaan chal raha hai.

ooainche bhavan, chimni tatha pul ityaadi ki neenv rachana mein hava, bhoochaal ityaadi dvaara jo kshaitij dabaav padta hai usaka bhi vichaar karna padta hai.

kai manjilvaale bhavan (sky scrapers) tatha bade pul ya meenaaron ki neenv ke liye kueain tatha latthon (piles) ka prayog kiya jaata hai. latthe lakdi, lohe ki dharan athva prabalit cement kankreet ke ho sakte hain aur latthe thonkane ke liye bhaap athva sanpeedit vaayu (compressed air) se chalanevaale-lattha thonkane ke sanyantron ka prayog kiya jaata hai.