Question

6.12 An excavation is made for a canal that is fed by a stream at the far edge of the excavation must be 0.5 m below the base. as shown in Figure P6.12. The measured flow into the 10 m /s per unit area. Two porewater line par- allel to the slope and approximately at the canal mid height gave readings of 3 kPa and 2.5 kPa. Assuming flow parallel to the slope, estimate the hydraulic conductivity. canal is 0.25 x (a) Calculate the radius of influence. pressure transducers, A and B, placed along a (b) Calculate the maximum drawdown (c) Plot the drawdown curve (d) For the radius of influence in (a), (i) calculate the discharge if the well radius increases to 0.2 m, and (i) compare it to the discharge for the 0.1-m-radius well 6.13 A well of 0.1 m radius is part of a wellpoint network to keep an excavation dry (Figure P6.13). The groundwater Flow Wellpaint Original GWL 2 m Excavation Drawdown 0.1 m 8 m 0.5 m k 5.8 10 ms =13.2. 104 m2s 8 m Impermeable FIGURE P6.13

Question 6.13 please

Answer 1

Sol Civen nle Radius Aocotid the excawation The Foo distamce 9.5 m the catr the well the at the wator 22 cx Lawation e wel Radiu 2 wate of water hu h the 2. that Kmow We the walufom the welk is pis charge ven (2 T K 13.2*D Given, ischar -m/s K 5-8X )0

TTx 5.8X ID x 3. 2 - \D q,5 135 w watar Height H the Now ( TiK H Aischange mR Yw ( 35 13.2XIO 2- 0 D5 Padius umce R = 226C2 m b Now far cd the excavation must the base o 5 m bellow the bc 9.5 M 2. Gwate h = w obsewed hight|

( 5.5-hu TK -4 3.2 X 1 D a.5 19.0 on solving 2 Araw douon h at Maximum :735 418 O.36 7 M Flow Actual dhawdown Draw doun Over utain duration 9.5m-

226.62 m d, In a, Radius R= with H = At radius 7.977 = = 02m well nadius (H-hu 132X16~ T32 XD e 735 5BXID X 226 C2 6 2 5 801 X (D Bis charge at o1m adius well 32 X16 ascharge at o2m adius welk 5801XID S4 due Discharge to inerwased Tncuased 0-2001 X ID diomata ot well