Numerical Simulation for the Seasonal Change of the Temperature and Humidity Field of Embankment in Moist Heat Areas

Abstract

Taking the meteorological data in Fuzhou area in 2011 as an example, this paper investigate the seasonal change of the temperature and humidity field of embankment in moist heat areas based on the finite difference technology programmed Moisture-heat coupled procedure. The results show that the highest temperature in the soil surface of embankment is near 40°C and the highest temperature gradient is up to 0.22°C/cm in summer. The lowest temperature is near 10°C and the highest temperature gradient is up to-0.21°C/cm in winter. Fluctuation range of the water content in the surface of the embankment (0cm~10cm) is between 3% and 20%, and fluctuation range of the water content of the shallow soil layer of embankment (10cm~50cm) is between 10% and 20%, and the water content in the deep layer of embankment (50cm~250cm) changes not apparently with season. If the temperature gradient of soil is 0°C/cm and the yearly fluctuation range of the water content of the embankment is 2%, the temperature and humidity of the embankment that can be affected by the climate of the Fuzhou area is in the depth of about 4.0m and 2.5m respectively.

Field Measurements and Numerical Simulations of Temperature and Moisture in Highway Engineering Using a Frequency Domain Reflectometry Sensor

“…From Figure 13 c, for sensor #1 embedded in the old subgrade, the measured values are substantially different from and even inconsistent with the values obtained through numerical calculation. According to deliberate analysis, the reason is that the moisture content in the old subgrade, having been subject to over a decade of operation, increases [ 13 ]; however, the newly-widened subgrade is filled under optimum moisture content conditions, so water migrates from the old subgrade to the new one, which causes a further decline of the moisture content in the old subgrade. In contrast, according to the calculated values, the moisture content in the old subgrade rises, because the moisture content values of the old and new subgrades are designed to be same when the mathematical model is established.…”

“…The infiltration coefficients of the subgrade and low liquid-limit clay are obtained through an indoor infiltration test, the thermal conductivity coefficient can also be obtained through an indoor test and calculation, the volumetric heat capacity and the physiological data of vegetation are values shown in [ 13 ]. The main parameters derived from the numerical calculation are given in Table 4 .…”

“…In most of the previous studies on highway construction or reconstruction/extension projects, the moisture content and temperature in the subgrade are subject to numerical simulation and calculation based on climatic parameters (temperature, moisture, wind speed, rainfall, evaporation and transpiration, underground water level, etc. ) [ 10 , 11 , 12 , 13 ]. Though certain effectivity has been achieved, the method requires many parameters, parameter acquisition is difficult and the calculations are complex [ 14 ].…”