J. Jpn. Soc. Soil Phys. No. +**, p.-/.+,**/ * Experimental Study of Water Redistribution Measurement in the Model Earthen Wall and its Numerical Analysis Takeshi ISHIZAKI* * National Research Institute for Cultural Properties, Tokyo Abstract In the Asian countries, there are many important wall paintings on earthen walls of temples and other historical buildings. Because earth can be considered as a porous material, there is water redistribution in the walls due to the change of the surrounding environmental conditions. Water evaporates under dry conditions from the wall surface and salts accumulate near the surface zone and can cause salt e%orescence damages in the wall paintings. In order to develop suitable protective measures, it is necessary to know the water content profiles and water movement in the earthen walls. For this purpose, a model earthen wall has been built up in the historical folklore museum in Sapporo. The water redistribution in the earthen wall was measured by using a TDR (Time Domain Reflectometry) apparatus. The numerical simulation of water movement in the model wall was performed with the Delphin. program developed by the TU Dresden. The material data, such as moisture retention curve, liquid water conductivity and water vapor di#usivity of the model earthen wall and climate data of the location Sapporo were taken into account for simulation. For development of suitable protective measures, it is quite important to have non destructive methods to understand the water regime in porous materials. The good agreement between simulation results and measured moisture profiles in position and time show the validity of using the Delphin. program for development and evaluation of conservation measures of historical buildings and stone monuments. Key words : historical building, earthen wall, water redistribution, TDR (time domain reflectometry), numerical analysis + * Ishizaki et al.,,**+..3,./,*** m, * ++*21+- +-.- : TDR
36 +**,**/ Kuchitsu and Xiuye, +331,**+,**+ + 0 TDR, + + Fig. + Japanese traditional house with earthen wall in Hokkaido Historical Village, Sapporo. cm - -+ +*2 cm +/ cm. cm, +** cm +/ cm. cm, +*2 cm + +** cm f + cm. / f / mm, - cm- cm,+ +1, 3 cm, / cm TDR.. 2 TDR Campbell scientific TDR+** CR+*X CR+* X CPU CR
µ ῌ : p ; QR¹ fºjg»¼ +*X PC,*2W EC +** PCTDR - TRIME-F-F TDR nq TDR!" #$ % & ' ( ) ' * - +, -./. cm, 01 0 mm 234 +, +.56 7 89:; < =2 >? @ABC5DEFG ij ktl m *. + 89:; -2ῌ ` opgqrst *, uvw _ Ix4 N yz p {/ 0 cm 23R TDR!" P#+ } P#/ I I ~ > P#, } P#0 -, I D r 'g HI JKKL M NOPQR STQRU2 / KL34 JK VW JKXY Z[ \] ^ KL ]_R ` 89:; > abcde -f; ) ' 37 TRIME-FM- g h+, %QR P#+, P#,, P#/, P#0 p Fr % / +3 mm,. mm, +. mm,. mm 23G \] '\ 5 Fr 2 4 '5 \R 53 4 4 ' QR 7 yz U z 8 4 ' Q R 7 E + R JK p 8 5FGN R, Ix4JK +. 2 GN W 5 [N]4 p ` ª5DEFG 89:; -/ῌ ` «pstgqr: 2D r ' y TDR!" P#-, P#1 ~ S %Q R p {/ + cm ' 1 cm \G P#-, P#1 p Fr % / g(. mm 23G P#,, P#0 KL + 2 Fr. mm 2 3G 5 + cm p {/5 ' 7 Fr +. mm qgn R JK p I ῌ, Fig., ῌFig. - Fr ij ² g x4 ` 4 R ±WN R Bamboo mesh structure of the model wall seen from the rear side. 89:; > 7 ³ TDR!" Tiny TDR sensor for measuring volumetric water content. ῌ. Fig.. ijp kt m Making earthen wall by putting mud on the bamboo.
38 +**,**/ - / -- P#-, P#1 1 cm TDR +2* cm 3* cm +* cm. +*.. + cm 2 cm P#., P#2 P#., P#2. mm 2 cm, TDR P#+, P#,, P#-, P#., P#/, P#0, P#1, P#2-3 mm,,. mm, +. mm,. mm, -. mm,,. mm, +. mm,. mm / 3 / /+ Water potential meter WP. Sald-*** -3 Grunewald and Bomberg,,**, / 0 / Fig. / Water retention curve ofthe soil used for the model wall.. HMP./C, -* + 0 Fig. 0 Sorption isotherm ofthe soil used for the model wall.
: 39 /, Burdine, +3/- q K q K cap K q cap Kq, + dq p cq p c q q K rq Kq Kq cap K cap KqK rqk cap f clay Dane and Puckett +33, K cap g..,+* / ms 1 /- m dry m dry Grunewald and Bomberg,**, p +p D VqT DT m dry q r qqdry q porq dry +q r p+q r, +p D T q por 2 0 Delphin. Grunewald,,*** +/ 3. TDR P#,, P#-, P#.,. mm, +. mm,. mm +. 1 Fig. 1 Liquid water conductivity of the soil used for the model wall. 2 Fig. 2 Vapor di#usivity of the soil used for the model wall.
40 +**,**/ +* + + + + +*. mm P#, -2 / + +.,. mm P#- + / -0 +* +. mm P#, +/, + cm -,. + cm 3 Fig. 3. Location of the monitoring position of water content (Stage.).. mm P#. +. mm P#-,. mm P#, +/ TDR Delphin. +. TDR 1 TDR +. Delphin. Delphin. +* +. Fig. +* Measured volumetric water content and calculated (Stage +.). Burdine (+3/-) : Relative permeability calculations from pore size distribution data. Petroleum Trans. Am. Inst. Mining Eng., +32 : 1+12.
: 41 Dane, J.H. and Puckett, W.E. (+33,) : Field Soil Hydraulic Properties Based on Physical and Mineralogical Information. In : van Genuchten M.T. et al. (ed.) (+33-), Proceedings of the International Workshop on Indirect Methods for Estimating the Hydraulic Properties of Unsaturated Soils, Riverside (California) USA, -23.*-. Grunewald, J. (,***) : Documentation of the Numerical Simulation Program DIM-.+, Volume + : Theoretical Fundamentals and Volume, : User s Guide. Delphin..+ program installation available on the ftp-server ftp : //+.+.-*..+.+3. of the Institute of Building Climatology. Grunewald, J. and Bomberg, M. (,**,) : An engineering approximation of material characteristics for input to Heat, Air and Moisture transport simulations. ++. Bauklimatisches Symposium an der TU Dresden. Ishizaki, T., Simunek, J. and van Genuchten, M. Th. (,**+) : Deterioration Mechanism of Stone, Brick and Soil Building Materials, Proc. Corrosion & Prevention-*+, Durability of Materials,.+st Annual Conference, Newcastle, Australia,,* : + +-. Kuchitsu, N. and Duan Xiuye. (+331) : Geological Environment of the Mogao Grottes at Dunghuang. Proc. of Conservation of Ancient Sites on the Silk Road,,..,.2. TDR Delphin. :,**/ / +2 :,**/ 0 3