To guarantee the rock stability between the
underground diaphragm wall and the karst cave during the concrete pouring stage
in the karst area, the form of force on the castinplace concrete underground diaphragm wall is analyzed. In addition,
the lateral pressure calculation formula of castinplace concrete is established based on Jassen theory. Then, the
simple analysis of the lateral pressure influencing factors is presented.
Moreover, on the basis of the nonlinear lateral
pressure calculation equation for castinplace concrete, the local linearization of the sidewall load of the
underground diaphragm wall is carried out and the determination method of the
safety factor for the local linear calculation is proposed. A method for
calculating the maximum bending moment of the castinplace underground diaphragm wall and the minimum safe thickness of
the karst cave sidewall bending resistance is obtained. Accordingly, the
stability analysis of the underground diaphragm wall and karst cave sidewall is
carried out. Finally, the analysis of the influencing factors is carried out
through typical engineering data, revealing the variation of the minimum safe
thickness of the karst sidewall with the vertical span of the cavern form, rock
tensile strength, burial depth, concrete slump, and casting time. The basic
principles of karst stability analysis of the lateral part of the karst
sidewall of the underground diaphragm wall are determined. The results of the
study show that the minimum safe thickness of the karst sidewall increases with
increasing burial depth, span, and concrete slump, and decreases with
increasing rock tensile strength and casting time. Based on the survey and
construction data, the stability of the rock formation should be analyzed
during the engineering design and stability evaluation, so that the evaluation
results can be more relevant to the actual situation.
TAN Junkun
,
QIAO Shifan
,
CAI Ziyong
,
ZHAO Yong
,
ZHANG Xibao
,
XIANG Nan
. Stability Analysis of Underground Diaphragm Wall and
Karst Sidewall Based on Janssen Theory[J]. Tunnel Construction, 2022
, 42(S2)
: 225
-233
.
DOI: 10.3973/j.issn.2096-4498.2022.S2.028
